Fix inconsistent CanvasModulate color in 2D HDR #35445

Job	Run time
📊 Static checks / Code style, file formatting, and docs	31s
🍎 macOS / Editor (target=editor, tests=yes)	3m 21s
🤖 Android / Editor (target=editor)	3m 55s
🍎 macOS / Template (target=template_release)	2m 52s
🤖 Android / Template arm32 (target=template_release, arch=arm32)	3m 12s
🤖 Android / Template arm64 (target=template_release, arch=arm64)	3m 15s
🍏 iOS / Template (target=template_release)	1m 38s
🐧 Linux / Editor w/ Mono (target=editor)	4m 46s
🌐 Web / Template w/ threads (target=template_release, threads=yes)	6m 5s
🐧 Linux / Editor with doubles and GCC sanitizers (target=editor, tests=yes, dev_build=yes, scu_build=yes, precision=double, use_asan=yes, use_ubsan=yes, linker=gold)	13m 13s
🏁 Windows / Editor (target=editor, tests=yes)	9m 59s
🐧 Linux / Editor with clang sanitizers (target=editor, tests=yes, dev_build=yes, use_asan=yes, use_ubsan=yes, use_llvm=yes, linker=lld)	7m 27s
🌐 Web / Template w/o threads (target=template_release, threads=no)	6m 12s
🏁 Windows / Template (target=template_release)	7m 32s
🐧 Linux / Editor with ThreadSanitizer (target=editor, tests=yes, dev_build=yes, use_tsan=yes, use_llvm=yes, linker=lld)	7m 29s
🐧 Linux / Template w/ Mono (target=template_release)	1m 10s
🐧 Linux / Minimal template (target=template_release, everything disabled)	52s
🪲 Godot CPP / Build and test Godot CPP	7m 56s
	1h 31m 25s

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