I have not tried it, but lichess is open-source : so you can probably customize it for your specific use case. More specifically modify line that allow to pic

I have not tried it, but lichess is open-source : so you can probably customize it for your specific use case. More specifically modify line that allow to pick the theme https://github.com/lichess-org/lila/blob/64b6f7966c8ed48dc904a47d842625b0533e6d31/modules/storm/src/main/StormSelector.scala#L20C15-L20C20 https://github.com/lichess-org/lila/blob/64b6f7966c8ed48dc90... With one of the value given here : https://github.com/lichess-org/lila/blob/64b6f7966c8ed48dc904a47d842625b0533e6d31/modules/puzzle/src/main/PuzzleTheme.scala#L18-L86 https://github.com/lichess-org/lila/blob/64b6f7966c8ed48dc90... ie : replace in stomSelector lila.puzzle.PuzzleTheme.mix.key by lila.puzzle.PuzzleTheme.defensiveMove.key and run a custom lichess as explained in the ReadMe