As a user on a much smaller forums, I have always taken an interest in reading texts in different colours, and the page in different colours. So like themes, I am rather delighted to see if we can have more themes, I do know which text colours would go well with them to avoid straining your eyes, here are a few of my own ideas.
All dark blue theme, text colour is white.
Pumpkin theme, the theme itself is orange while the text is moderate green on a moderate orange.
Wintery theme, this one is a bit unique, maybe the top and sides of the screen should have snowflakes while the rest of the screen is a lovely night sky, text should be white. Or a day version of it with a light blue sky and black text.
Pink theme, the text is dark green.
Rainbow theme, the top left right have the 7 colours of rainbow in nice stripes over a light blue screen while the text itself is dark blue.
I hope you like these ideas, if i went too ambitious with them then that’s ok.