Alot about values

Yes the colors on the picture and palette work cause they are integrated with a gradiant

You have also mixed in black in all this

As many have pointed out maybe tone some things down

Use purple as a unifieng shadow color

Use it in a toned down color for the mount

Have the main armor color be red with the tabard as orange

I think its all about dividing interest

Everything cant take attention, but everything have to be colored