Walker Ceramics Design Colours are like "poster paint" for clay. You can decorate with confidence as all colours reflect the final fired colour, except for FK21 Cobalt Sea , which appears mauve in the bottle but actually fire a deep, vibrant blue. This means that you can use our creativity & decorate your work trusting your eye. Design colours are easy to use and are suitable for greenware and bisqueware. They are suitable for all skill levels and techniques, even majolica; they bring clay to life. The colours are flowing and can be extended using our Flux Extender for translucent effects.