When using expanded color_palettes for trims as described by JAPPA here Bedrock doesn't seem to apply the extended palettes correctly (see screenshot bedrock.png).

The same extended color_palettes work fine on Java (see screenshot java.png).

HD packs being limited to 8 colours is going to make things very difficult to make them not look poor/low definition.

In both screenshots it's Iron Armour, with a Dune trim, and Gold Ingot colouring. Both should look the same, or very similar, however in Bedrock the colour is a lot darker, and has lots of weird speckles caused by the custom palette not being used.

The extendedcolorpalette.mcaddon is attached for a dev to test.