[OSD] Colorize percentage text when over 100%
We've now made it easier to increase the maximum volume to 150% for those who need it due to quiet speakers. However since this could potentially lead to excessive volume or damage to loud speakers with long-term use, let's colorize the text to subtly indicate that this is not a normal state.
Requires plasma-pa!8 (merged)
With that also applied, here's how it looks: