I've been thinking about a way to let my CSS do ALL of the formatting > in special the application colors.
Problem: not all elements (ie. beans, bg calculation) are supported.
I came up with the following solution:
1) create label styleclasses with the colorproperty set as you want it.
2) create a 'dummy' form with different labels to which you assign the styleclass you just created (also use element names)
3) use the element fgcolor-property to 'read' the color assigned to the label on your dummy form and use this value to set the color.
I hope this can be usefull to other people.