I'm guessing that's because blue means left wing in the USA and red means right wing.

Why did you switch them around? Red always meant left wing. Even in the US red meant the Soviets. It's just confusing to everyone else.

no one really knows, when broadcasters started using party colors it was all over the place and they settled on blue for dems. i guess its because neither party was socialist so there was no association with red like in europe.