Unfortunately, the Help is well out of date.
Go to: OPTIONS > APPLICATION > CHANGE APPEARANCE and you will add a customising toolbar to your forum. Select the COLOR option and a dialogue appears:
On this dialogue you can
# Pick pre-made schemes from the COLOR SCHEMES button
# Edit individual colours
# Restore the Defaults.
Just click the APPLY button to confirm your changes or the X button to abandon them.
Once you've finished making changes on any of the other toolbar buttons, don't forget to CLOSE the toolbar to commit everything so your users the changes you have made.
Volunteer Helper - but recommending that users move off the platform!
Once the admin for GregHelp now deleted.