Allow text_color parameter to accept ColorPalette in core.py

[SkalskiP]

Description

Changed the text_color parameter in core.py to accept ColorPalette in addition to Color. Previously, it only accepted input of type Color. Now, it also accepts the type ColorPalette, which increases the flexibility of the text color choice.

Type of change

Please delete options that are not relevant.

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] This change requires a documentation update

Docs

• [x] Docs updated? What were the changes: