Yes, you can use SET SPRITE DIFFUSE to change the color to whatever you want. But if you want it to be colored exactly the red, green, and blue content you want the sprite needs to be a white version of the sprite. Any color differences in the sprite will throw off the look after using SET SPRITE DIFFUSE.
` Make a white box
ink rgb(255,255,255),0
box 0,0,100,100
get image 1,0,0,100,100,1
` Make a red box
ink rgb(255,0,0),0
box 0,0,100,100
get image 2,0,0,100,100,1
` Make two sprites
sprite 1,50,50,1
sprite 2,200,50,2
` Change the color of the sprites to blue
set sprite diffuse 1,0,0,200
set sprite diffuse 2,0,0,200
wait key
In the above snip only the white box changes color properly.