Cello question? Yellow= age?

Well this shop down the street has a bunch of stuff I have never heard of or seen before but does look promising for a cheap stick. Looking around the place about a third of the stuff has yellow cello.
I understand that just because something is older/aged it doesn't mean it is going to be good.
The coloring is what I would consider coloring from aging. Thanks for the time and for answering everyone.