Yes, it works. Thanks!
Here is my script:
;Set MagicWB colors in AROS
setpencolor SCREEN="Workbench" PEN=0 COLOR=$959595
setpencolor SCREEN="Workbench" PEN=3 COLOR=$A2673B
setpencolor SCREEN="Workbench" PEN=4 COLOR=$7B7B7B
setpencolor SCREEN="Workbench" PEN=5 COLOR=$AFAFAF
setpencolor SCREEN="Workbench" PEN=6 COLOR=$7C90AA
setpencolor SCREEN="Workbench" PEN=7 COLOR=$97A9FF