I was looking for that kind of software as well.
Then I found the .cube specification.
I thought to myself ... an average programmer should be able to do it in a couple of days ... and then I did the ...
Not a colour expert, but I think:
YCbCr is just a mathematically different way of representing RGB.
Y is luminance, Cb and Cr are mathematically derived ways of representing the other colours.
It is ...