Looks like it needs a shot of brown or black...or something else, not sure
I did a Virginia Tech cake with that color. I mixed a lot of red and some burgundy. I also added some cocoa powder, and that really seemed to help!
Try letting the icing sit for a few hours and see if the color darkens.
I did a A&M cake with a dark maroon and my color looked about like that until I let it rest over night and it was perfect in the morning.