Hi,
To add an extra color options to the template configuration :
Edit the templates/rt_cerulean/template-options.xml. The filed for the option you want to update is defined from Line #51 to #56.
Copy any option line like
<option value="orangecolor">ORANGE</option>
and paste it to now have something like this :
<option value="redcolor">RED</option>
<option value="bluecolor">BLUE</option>
<option value="greencolor">GREEN</option>
<option value="orangecolor">ORANGE</option>
<option value="mycolor">My color</option>
change 'mycolor' with the color value you want (only letters, avoid special characters) and My color with the text you want in the template configuration page.
Save. If you refresh your template configuration page, you should now see the new option in the list. You can select it and save.
In the 'templates/rt_cerulean/images/accent2' folder, you have 1 folder per accent2 option value.
So just copy an existing folder and rename the copy with the option value you've set previously ('mycolor' in this example).
Update the images of your color folder and you should be good.
Olivier