[Feature Request] Set custom Collapse header colours.

### Existing Component
Yes

### Component Name
Collapse

### Description
Could you make it possible to set dynamic collapse header colours.
If you could also set open/closed/disabled colours as dynamic for each collapse item also that would be amazing.
This would help style easier when you have long lists of collapse or accordians.

Start by locating the Collapse component and reviewing how its headers and open, closed, and disabled states are styled. Check existing component documentation and examples to determine the supported customization patterns; done means agreeing on the dynamic color API and documenting or testing the intended behavior for each collapse item.

Written by the indexing model from the issue text.