Empire Captain WIP

I've been working on this guy a few minutes at a time for the past few weeks. I wasn't very happy with him initially but the more I do the more I like him. However, I've come to a problem and I need some help.

His major colors are the purple, yellow, and armour and I have to paint his shield and cape. I don't think any of those colors would make a good cape or shield (maybe a the armour color would be good on the shield but there is so much metal already) but I can't come up with any other colors to pair with them. Take a look:

I considered a gray cloak (but that's pretty similar to the armour) and a wooden shield but I'm just not liking any of my ideas. So, does anyone have any thoughts?