PLAYRTS-5579 Add RTS humour topic colors

[pyby]

Description

RTS editors added a new topic: https://www.rts.ch/play/tv/categories/humour

New topic colors for the gradient can be added.

Changes Made

• Update the local topicColors properties with RTS humour new gradient colors.

Checklist

• I have followed the project's style guidelines.
• I have performed a self-review of my own changes.
• I have made corresponding changes to the documentation.
• My changes do not generate new warnings.
• I have tested my changes and I am confident that it works as expected and doesn't introduce any known regressions.
• I have reviewed the contribution guidelines.