When i was deciding on a color for doodle the original concept was merely to have her be colored like airbrush but have a different name which gave her the blue mane and pink body.

I went on later to say that if my fanfiction i was writing (still working on it) had ended with Starscream marrying Airbrush, (it doesn't by the way) doodle would have been the result. Her color pallet would then have been a lighter pink, and a blonde mane to reflect her father's hair.

When I made the decison to go with a more natural horse's color the first thing that popped into my head was a painted-horse colored pony with a brown mane and tail light reddish brown fur with chestnut spots. However i reminded myself that if i was going to turn Isla Aukake into a comic id have to draw doodle repeatedly, over and over again, and having too many details on her face would be easily forgotten page to page.

So i opted for the somewhat simpler design of the nose stripe blond hair and roan fur with light reddish white "socks and a blonde mane, firstly because i love the contrast and secondly as a none-to-subtle call back to the notion that in a different universe she was, by blood, Starscream's daughter.