Explore gradient colouring

Add gradient colour options that adds a colour list block with the gradient colours populated in order. 

Needs investigation but potential to include two colours as default but expand to more and change the gradient style or direction. 

See discord example below:

<img width="372" height="150" alt="Image" src="https://github.com/user-attachments/assets/577050d1-3b91-420e-bde6-3c4ab503f5df" />