Let me know if it works!
The class I mainly use is .put-art-here (which corresponds to the text entry area). I've changed width, margin, and padding on that before, but never tried with the colours.
I think* you might be able to customise the title entry area too, but only if you use
input
or something like that - and I'm not entirely sure if it works, think I might've tried once and failed (or maybe not, I can't entirely remember
)