Change colors of the calendars?

I read the help and thought the Gadget displays calendars in the color that is set in Google Calendar, but the colors are random(?) and I can't change them. They are hard to read and I can't distinguish them.
It would be really nice if I could get help with the colors. Right now I can't neither read the events properly nor differentiate between them.

Also: Is there a ways to have a dark grey background instead of only black? That wouldn't be so hard on the eyes.


Thank you!

Yes, colors should be the same as calendars are displayed in Google Calendar. Btw I suggest choosing "Mark" for "Use colors" setting because this way only a colored mark is displayed instead of colored text. To be frank, I hate colored text, I only included that feature because of user requests.

For gray background: have you checked "Default" and "Default old" themes? There are "nicer" themes available in Googler