I would do something with the accent colours.
You need to pick one, blue purple and yellow is to many.
Personally I think you should lose the blue and go for purple on the seals, and then you need more yellow on the shield. Try painting it all yellow over a white or grey base coat, then wash with sepia or brown for shade, then highlight the edges. You should get a better gradient of colour. You can use the same technique for the bone cloth just highlight with bone then extreme with white. For bone colour or yellow I use a watered down mix of whatever snakebite leather is called now for the shade. Try 60/40 water to paint and then adjust your ratio to taste.
Hope it helps