YCbCr
A family of colour spaces, used in some HD applications, where colour is expressed using a luma component plus red and blue chroma components, rather than by describing absolute color values, as in the RGB colour model.
The difference between YCbCr and RGB is that YCbCr represents color as brightness and two colour difference signals, while RGB represents colour as red, green and blue. In YCbCr, the Y is the the brightness (luma), Cb is blue minus luma (B-Y) and Cr is red minus luma (R-Y).
The analog counterpart of YcbCr is YpbPr.