color.module unsupported operand types

Hi, I've recently upgraded one of my sites from Drupal 6.20 to 7. I disabled and deleted all contributed themes and modules before upgrading (although I left their data in the database). The Drupal 7 upgrade went fine, and I installed RootCandy 7.x-1.x dev. However, when I try to pull up its settings, I get this error message:

Fatal error: Unsupported operand types in /home/dtdrupal/stable/modules/color/color.module on line 158

Any ideas as to what I am doing wrong? I don't think this is an error with the color module, as I can pull up settings on all other themes that come with D7. I've tried the following:

• clearing the cache/rebuilding the theme registry
• running update.php (it said no updates were available, which strikes me as odd)
• making sure all traces of the old RootCandy 6.x theme were gone

Currently, I only have core modules and themes enabled.