PAINT WHITE OVER DARK GREEN DRYWALL
If I understand you correctly, you can use a paint sprayer. Buy or rent one, depending on other uses you might have w/it.
My best to ya and hope this helps.
Jay J -Moderator
PS: They do make nap rollers for this. Visit your local Paint Retailer (found in the YELLOW PAGES under PAINT - RETAIL) for more info.