I don't really think that the colors are working out that well. I'm having a hard time imagining the continuum of colors between red and blue. Mapping the variable (percentage of votes for either party) to saturation or brightness of a certain hue would be more straightforward and intuitive. Although, it would make for a pretty lousy political statement as compared to purple :)

Another way to make the two basic colors more interesting could be the delta between the state and 50% and mapping it to saturation in both directions, i.e. CA dark blue, OH light blue, UT darker red… but I'm pretty sure some news outlets already did that.

All it needs is a key showing what shade is 50/50. Unfortunately one isn't provided...