color help

Hi i'm a bit of a noob when it comes to flash i've got most of the basics but one thing is more slowing me down than stopping me

i have used sprite sheets and bitmaped them, however It is hard to remove the entire BG that they tend to come with due to tight gaps

i was wondering is there a way to tell the program to highlight a specific color so you can delete it all at once, cause that would really save time

You could use Photoshop or other graphics program to select and remove the color to be used as transparent, then save the bitmaps as a PNG with an alpha channel.