It’s one of those fake TikTok “facts” that’s only kind of true. The Heelers are blue/orange, which does work decently well with Deuteranopia (red-green color blindness), and is closest to what dogs’ vision is like. But it’s mostly just a coincidence, and there’s plenty of cases where scenes really don’t work well if you run them through a Deuteranopia filter, and Chili/Bingo really blend into the background a lot of the time.