the color is reset when adding the morph to the SystemWindow (see 
SystemWindow>>addMorph:fullFrame:) - don't know why

try to set the color after adding it, not before.

Herbert König wrote:
> [...]
> Problem is: the button ignores the setting of the colour and comes up
> with Color transparent, though it accepts a new colour from from a workspace.
 > [...]
> "================ the following line is ignored Why??? =============="
> 
>         self firstPathButton color: self firstPathButtonColor.
>         self firstPathButton onColor: self firstPathButtonColor offColor: self firstPathButtonColor.
> 
> 
>         "=== assemble the whole ... ==="
>         uiWindow addMorph: self firstPathButton frame: (0.0 @ 0.0 extent: 1.0 @ 0.2).
> [...]