Huh? You just did right? The darkred background color.
COLOR A,B
A and B are both numbers from 0-15, A for foreground, B for background. (example: COLOR 3,8)
You can also use labels starting with #T instead, such as COLOR #TYELLOW,#TRED
Also, for the line
SPOFS 0,150+X,100+Y
You can play around with the numbers (don't change the 0), such as
SPOFS 0,170-X*2,193+Y*3
Go crazy!
0そうだね 未プレイ