Common Error 1

Fatal error: Call to undefined function _color_page_alter() in /path/to/drupal/themes/garland/template.php on line 60
Why: You are not using color.module NG themes

How to fix: move the themes from /examples into /themes.

Common Error 2

Out of memory or user warning: Table 'mytablename.color_schemes' doesn't exist
Issue: #334580

Why: Tables not created yet

How to fix: You will have to disable, uninstall, then re-enable through your admin/build/themes page.