I think the red on the back looks good, nice deep shadows. And I like using the dark sea blue as a shadow color. I think the front could use a bit more contrast, more shadows and highlights. But as Skel says, without the gold it's a bit hard to judge.
What are you trying to do with the red? Is it supposed to be some red fantasy metal or red paint over armor? If you're going for more of a red metal finish then you should push the highlights more. I did a really extreme contrast red a
while back in my thread. If I recall correctly I went from Burgundy Wine up through the bright reds (Andrea Red Set), then mixed in white to my brightest red. I then applied a couple layers of GW's Bloodletter Glaze to take the slightly pink highlights back to red, then touched up a few of the white highlights. Definitely a challenge. Best advice is keep the area where you leave the red (by adding white, yellow, skin tone, whatever) as small as possible. The red glazes will help, but large areas outside the traditional reds will skew the end result.
