Originally Posted by vadalia

As for what color B you might want to buy instead good question. You have a little bit of blue here and there with some of your other fabric Cs (but it's not an all-over color in those fabrics like the orange & red is in their's) so blue might be a good option to tie things together without being too jarring. Or you could go extreme and up the contrast with a dark purple, since that makes up a triadic color scheme with the orange & green also prominent in your fabrics Good luck!