Why YCrCb?

[Code\\Pilot]

I was looking at the camera code and i noticed that the tracking of green changes to yCrCb. Why is that?
"rom const char *yCrCb_mode = "CR 18 0"; // Set into yCrCb mode instead of RGB"

[probizzle]

YCrCb is less sensitive to lighting changes, where lighting changes are changes in "warmthness" of a picture (ie whether the light is more blue "cooler" or whether it is more yellow/red "warmer").

Not an expert though.

[russell]

So shouldnt they use it for all of the colors....?