$ echo -e "EnableLinuxHWVideoDecode=1\nOverrideGPUValidation=true" | sudo tee /etc/adobe/mms.cfg
Then on YouTube, 360p and 480p videos had proper tint. But 720p videos still were blue. And Flash crashed regularly. After removing that file, all YouTube videos are tinted blue, and Flash doesn't crash.
To clarify, after doing:
$ echo -e "EnableLinuxHWV ideoDecode= 1\nOverrideGPUV alidation= true" | sudo tee /etc/adobe/mms.cfg
Then on YouTube, 360p and 480p videos had proper tint. But 720p videos still were blue. And Flash crashed regularly. After removing that file, all YouTube videos are tinted blue, and Flash doesn't crash.