What colour is roan?

There can be a blue roan, a bay roan, and a red roan. A roan is a horse with a regular coat colour with white hairs sprinkled without it. Red roans and bay roans are very similar in colour, but they are still different. I love roans and they truly are beautiful horses.

A red roan: http://www.barrelracer.com/Dusty%20Gildner/red%20roan%20filly.jpg
A bay roan: http://www.holderquarterhorses.com/marthas-six-moon-colt-3.jpg
A blue roan: http://www.horsemadness.com/poco3.jpg