Suggestion: add some optional mini-tournaments which only knights of a specific color can enter.

Example;
- Black Knight Tournament : knights may only be equipped with black armor and weapons.
- Green Knight Tournament : etc.
- Blue Knight Tournament : etc.
- Demon Knight Tournament : etc.

If there are multiple types of tournament available simultaneously (e.g. a drop-down to select the tournament ), then player can choose the regular tournament or one of the others, but only enter one tournament per day. The special tournaments have smaller prizes. But smaller knights then have an option to beat on each other.

Side effect:
Armor of other colors acquires values. Right now black armor is worthless after the 2nd day of play, and green and blue not much better.