diff --git a/extensions/theme-defaults/themes/dark_plus.json b/extensions/theme-defaults/themes/dark_plus.json
index 4fd89793214..e928b63cfb2 100644
--- a/extensions/theme-defaults/themes/dark_plus.json
+++ b/extensions/theme-defaults/themes/dark_plus.json
@@ -91,7 +91,8 @@
 				"variable",
 				"meta.definition.variable.name",
 				"support.variable",
-				"entity.name.variable"
+				"entity.name.variable",
+				"constant.other.placeholder", // placeholders in strings
 			],
 			"settings": {
 				"foreground": "#9CDCFE"
diff --git a/extensions/theme-defaults/themes/light_plus.json b/extensions/theme-defaults/themes/light_plus.json
index cbae5efd227..62f15133ea3 100644
--- a/extensions/theme-defaults/themes/light_plus.json
+++ b/extensions/theme-defaults/themes/light_plus.json
@@ -91,7 +91,9 @@
 				"variable",
 				"meta.definition.variable.name",
 				"support.variable",
-				"entity.name.variable"
+				"entity.name.variable",
+				"constant.other.placeholder", // placeholders in strings
+
 			],
 			"settings": {
 				"foreground": "#001080"
diff --git a/extensions/vscode-colorize-tests/test/colorize-results/test_c.json b/extensions/vscode-colorize-tests/test/colorize-results/test_c.json
index 30fd5393c47..0aa8431e452 100644
--- a/extensions/vscode-colorize-tests/test/colorize-results/test_c.json
+++ b/extensions/vscode-colorize-tests/test/colorize-results/test_c.json
@@ -641,8 +641,8 @@
 		"c": "%f%f%f",
 		"t": "source.c meta.block.c meta.function-call.c string.quoted.double.c constant.other.placeholder.c",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
@@ -1499,8 +1499,8 @@
 		"c": "%.2f",
 		"t": "source.c meta.block.c meta.function-call.c string.quoted.double.c constant.other.placeholder.c",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
@@ -1521,8 +1521,8 @@
 		"c": "%.2f",
 		"t": "source.c meta.block.c meta.function-call.c string.quoted.double.c constant.other.placeholder.c",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
@@ -1972,8 +1972,8 @@
 		"c": "%.2f",
 		"t": "source.c meta.block.c meta.function-call.c string.quoted.double.c constant.other.placeholder.c",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
@@ -1994,8 +1994,8 @@
 		"c": "%.2f",
 		"t": "source.c meta.block.c meta.function-call.c string.quoted.double.c constant.other.placeholder.c",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
@@ -2500,8 +2500,8 @@
 		"c": "%.2f",
 		"t": "source.c meta.block.c meta.function-call.c string.quoted.double.c constant.other.placeholder.c",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
@@ -2522,8 +2522,8 @@
 		"c": "%.2f",
 		"t": "source.c meta.block.c meta.function-call.c string.quoted.double.c constant.other.placeholder.c",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
@@ -2544,8 +2544,8 @@
 		"c": "%.2f",
 		"t": "source.c meta.block.c meta.function-call.c string.quoted.double.c constant.other.placeholder.c",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
@@ -2566,8 +2566,8 @@
 		"c": "%.2f",
 		"t": "source.c meta.block.c meta.function-call.c string.quoted.double.c constant.other.placeholder.c",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
@@ -2793,4 +2793,4 @@
 			"hc_black": "default: #FFFFFF"
 		}
 	}
-]
+]
\ No newline at end of file
diff --git a/extensions/vscode-colorize-tests/test/colorize-results/test_cc.json b/extensions/vscode-colorize-tests/test/colorize-results/test_cc.json
index cb2fb192e1d..4b04cef1c5d 100644
--- a/extensions/vscode-colorize-tests/test/colorize-results/test_cc.json
+++ b/extensions/vscode-colorize-tests/test/colorize-results/test_cc.json
@@ -124,8 +124,8 @@
 		"c": "%d",
 		"t": "source.cpp string.quoted.double.cpp constant.other.placeholder",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
@@ -432,8 +432,8 @@
 		"c": "%d",
 		"t": "source.cpp string.quoted.double.cpp constant.other.placeholder",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
@@ -1466,8 +1466,8 @@
 		"c": "%s",
 		"t": "source.cpp meta.function.definition.cpp meta.body.function.definition.cpp string.quoted.double.cpp constant.other.placeholder",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
@@ -1488,8 +1488,8 @@
 		"c": "%s",
 		"t": "source.cpp meta.function.definition.cpp meta.body.function.definition.cpp string.quoted.double.cpp constant.other.placeholder",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
diff --git a/extensions/vscode-colorize-tests/test/colorize-results/test_cu.json b/extensions/vscode-colorize-tests/test/colorize-results/test_cu.json
index 21c8a0613c3..6a652e7a3e9 100644
--- a/extensions/vscode-colorize-tests/test/colorize-results/test_cu.json
+++ b/extensions/vscode-colorize-tests/test/colorize-results/test_cu.json
@@ -806,8 +806,8 @@
 		"c": "%s",
 		"t": "source.cuda-cpp meta.preprocessor.macro.cuda-cpp meta.block.cpp meta.block.cpp string.quoted.double.cpp constant.other.placeholder",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
@@ -839,8 +839,8 @@
 		"c": "%s",
 		"t": "source.cuda-cpp meta.preprocessor.macro.cuda-cpp meta.block.cpp meta.block.cpp string.quoted.double.cpp constant.other.placeholder",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
@@ -861,8 +861,8 @@
 		"c": "%d",
 		"t": "source.cuda-cpp meta.preprocessor.macro.cuda-cpp meta.block.cpp meta.block.cpp string.quoted.double.cpp constant.other.placeholder",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
@@ -1752,8 +1752,8 @@
 		"c": "%s",
 		"t": "source.cuda-cpp meta.preprocessor.macro.cuda-cpp meta.block.cpp meta.block.cpp string.quoted.double.cpp constant.other.placeholder",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
@@ -1785,8 +1785,8 @@
 		"c": "%x",
 		"t": "source.cuda-cpp meta.preprocessor.macro.cuda-cpp meta.block.cpp meta.block.cpp string.quoted.double.cpp constant.other.placeholder",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
@@ -1807,8 +1807,8 @@
 		"c": "%s",
 		"t": "source.cuda-cpp meta.preprocessor.macro.cuda-cpp meta.block.cpp meta.block.cpp string.quoted.double.cpp constant.other.placeholder",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
@@ -1829,8 +1829,8 @@
 		"c": "%d",
 		"t": "source.cuda-cpp meta.preprocessor.macro.cuda-cpp meta.block.cpp meta.block.cpp string.quoted.double.cpp constant.other.placeholder",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
@@ -11344,8 +11344,8 @@
 		"c": "%u",
 		"t": "source.cuda-cpp meta.function.definition.cuda-cpp meta.body.function.definition.cuda-cpp meta.block.cuda-cpp meta.block.cuda-cpp string.quoted.double.cuda-cpp constant.other.placeholder",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
@@ -11366,8 +11366,8 @@
 		"c": "%u",
 		"t": "source.cuda-cpp meta.function.definition.cuda-cpp meta.body.function.definition.cuda-cpp meta.block.cuda-cpp meta.block.cuda-cpp string.quoted.double.cuda-cpp constant.other.placeholder",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
@@ -11388,8 +11388,8 @@
 		"c": "%u",
 		"t": "source.cuda-cpp meta.function.definition.cuda-cpp meta.body.function.definition.cuda-cpp meta.block.cuda-cpp meta.block.cuda-cpp string.quoted.double.cuda-cpp constant.other.placeholder",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
diff --git a/extensions/vscode-colorize-tests/test/colorize-results/test_go.json b/extensions/vscode-colorize-tests/test/colorize-results/test_go.json
index 14cd6ef4230..73169efcc2c 100644
--- a/extensions/vscode-colorize-tests/test/colorize-results/test_go.json
+++ b/extensions/vscode-colorize-tests/test/colorize-results/test_go.json
@@ -1257,8 +1257,8 @@
 		"c": "%s",
 		"t": "source.go string.quoted.double.go constant.other.placeholder.go",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"
@@ -1279,8 +1279,8 @@
 		"c": "%s",
 		"t": "source.go string.quoted.double.go constant.other.placeholder.go",
 		"r": {
-			"dark_plus": "string: #CE9178",
-			"light_plus": "string: #A31515",
+			"dark_plus": "constant.other.placeholder: #9CDCFE",
+			"light_plus": "constant.other.placeholder: #001080",
 			"dark_vs": "string: #CE9178",
 			"light_vs": "string: #A31515",
 			"hc_black": "string: #CE9178"