Color has nothing to do with which drop it is...drop 10 is the same as 9 and 11.
All are white with a color accent. There is only 3 bats in the Mizuno lineup (besides the drop13 which is different)...One is a one piece, the other is a Titanium and the other is the Power Carbon. The PC is white with Blue/purple...whatever your eyes see it as...haha
I will vouch for the F21. We’ve had the F19, F20, and now the F21. It is definitely a bit hotter and even some mishits get hit hard! You will also not find a better deal than what you will get with Core.