Purple (and other new themes) to more purple to be able to see black color names in chat

The new purple theme looks fantastic and I'd love to use it but I can't see people with black color names in chats. The Purple turns into black too fast and it's primarily black in the chat, preventing from seeing black names on a black background (in chat and member list). So my question is: is it possible to make the purple continue longer as purple and not turn black as fast? I still want it to be dark but to be able to see black names too.