When changing the ruleset at song select, there was a scenario where it
would be set to default (empty) for one debounce length where this was
not actually required. This occurs when the currently selected beatmap
set has other difficulties which match the target ruleset, specifically.
I tried also updating the colours to the "new" versions from designs but
they don't match due to colour profile differences (so I'm not yet sure
if they are correct or not) and also don't look great without all the UI
elements also being updated.