Custom Color Picker in Rich Text Editor (React & React Native)

Summary
Add a custom color picker to the Rich Text Editor in both React and React Native.

Problem
Currently limited color options restrict formatting flexibility.

Proposed Solution

• Allow custom text and background colors

• Support HEX/RGB input

• Include color palette + recent colors

• Ensure consistency across React & React Native

Impact
Improves user experience and enables better content customization.