It sounds like you have a case of algae. there are product available at your hardware that can clean this stuff of. A pressure cleaner and a bit of bleach should have it looking as good as new.
they are red and black and spotted
One's black and one's spotted....Derr
Black smoke poured into the bus.
pied
Black-spotted ridge-tailed monitor was created in 1987.
no
A beetle is a small round bug with a hard shell. There are several beetles that are black spotted. One example of a black spotted beetle is a lady bug.
black
Why don't white people with dark hair have black skin?
Black panthers are either a melanistic (black) jaguar or a melanistic leopard. It is a rare recessive genetic trait. A leopard is usually born spotted and cannot change to a black leopard and a black leopard cannot change to a spotted leopard. Genetics at fertilization determines the color.
black and yellow
The black spotted dog that works at fire stations is spelled "Dalmatian."