I have had great results mixing citra and amarillo.
Also, I once used a similar amount of roast barley in a red ale just to add colour. No noticeable roastiness on the pallette so I think you might get away with it.
FYI, I would, however, be a lot more cautious using black malt for colouring as it can have quite a presence even at 2%. Made a porter that was undrinkable for the first 3 months while waiting for the black flavours to mellow out.