Komodo-Macros is a project mainly written in ..., it's free.
Macros for Komodo and Komodo Edit
A set of macros for Komodo IDE/Edit.
Generates/shows an auto-complete popup for the hex colors you've listed in the first comment block of your CSS file.
After you've added the macro to your toolbox, you can add a key binding to execute it whenever you want. (I'm using Ctrl+Alt+K.)