I was trying to setup a default color scheme since Max7 came out. I would manage to do so but the custom colors would always get lost.
Finally got it to work with the help of Ben one the C74 support techs.
Here is a walk-through of the setup steps:
1. in a default patcher, make a bunch of objects and then in the Format Palette,change them to whatever colors you want
2. select all the objects in the patcher
3. in the Format palette, make a new style – this style will be for multiple objects
4. select the patcher to activate it in the Format palette
5. In the Style menu (located in the patcher inspector window), select the style you just made, applying it to the patcher level
6. delete all of the objects in the patcher
7. save a new template (in dropdown file menu "create template") and make it your default
Hope this helps