Create a form with some components (tested JButtons) with assigned foreground and background colors from swing palette (UIManager.getColor("name")). Make sure these colors are shown when you run the main() method of the form. Run form preview. Colors are shown - Ok. Switch preview look and feel to any value, e.g. to the same value. Result: all colors are shown default. This happens only with swing colors, neither with numeric values (RGB/HSB/Swatches), nor with System colors (Systemcolor.), nor with AWT Palette (Color.).