For this only high-graded structural members are used. It is offerd in modern forms and surface structures, in various hues or permeable to light. For example around the fitting of the shower you can set tinted or colourful glas bricks. Out of glas bricks you can build piece- or full wall elements, shower walls or pieces of the room. The simplest possibility, to bring colour in your bath, are colourful towels and colourful bath carpets.
Colourful fittings are another possibility, but mostly it is an expensive version.
For somebody a golden fitting is pure luxury, but for others it is only an extra colour version. That is an unpleasant view and the double work for you. And the drops also take extra mud and lime with them. And the less deposition comes into the being, the better it is for you, you do not have to clean your bath that often. Particularly this means, that you do not have to use sharp detergents, and this is good for our environment.