hm, aint looking bad. Can you also do those in a nice blue (like dark blue as the Nordmen use their banner)? That is not a bad idea, the more armors in many colours the better.
You know it would also be amazing if there was a way to trade the same item's colours. Example, trading Blue Coat of Plates +3 (+0,+1,+2) for Green Coat of Plates for example (npc-wise, for a little gold fee, Im not talking about trading an armor for another item).
What I always missed were more colours. When I was in HRE, I missed some heavier gear in yellow for example. 
The armor uses the background color of your current banner, so there is only 1 armor, called "Colored Tabard". The yellow one in the screenshot uses the native HRE banner. However, the color will not exactly be the one of the banner, because a) it uses the BACK_COLOR of the banner, which is sometimes different than the banner's background color (confusing, I know), and b) the blending process can produce slightly different results, because it's hard to make it look good for both dark and light colors.
The reason why I didn't make it heraldic, btw, is because if you add the heraldic symbol, it also adds another layer of the banner background color, which produces visible seams in the colored area. Also, there are many armors that could be colorized using this technique, but that don't have an appropriate area to display the symbol.
Poll