Typically in colors of blue or black, a foam roller is quite simple: a cylinder made of foam (usually about 6 inches in diameter and about 18 inches long). (femmefitalefitclub.com)
I just purchased a similar color of blue paint for an old lamp. (theinspiredroom.net)
I may have missed it somewhere, but what color of blue is that on the walls? (atthepicketfence.com)