Pre-coloured grouts tend to come in a range of fairly standard colours; white, black, brown, beige, and grey. So what do you do it your after something different? Why not try colouring it yourself!
There are a few different ways to colour grout, powdered pigment / cement oxides or acrylic paint.
Powered pigments or cement oxides can be purchased from hardware stores as they are used for colouring cement. The draw back to this option is the quantities the cement oxide are sold in, as it is used to colour grout cement the purchase size is large. When using powered pigment or cement oxides, add the powder to the dry grout and mix before adding the water. Just remember that the colour will appear a few shades darker when wet.
The other option is acrylic paint. The advantage to this colourant is the range of colours that you can create. You should also bear in mind that opinions vary on the use of acrylic paint as a colourant. Many books suggest using it as a colourant but others point out the following negatives: it requires lots of paint, it can produce a pale coloured grout and may affect the integrity of the grout itself. If you choose to colour your grout with acrylic paint, add it to the mixed grout. You will need to reduce the amount of water you add as the paint is a liquid.
With both options make sure you mix enough grout to complete your project, colouring matching is pretty much impossible when you mix the grout yourself.
The birdbath below is by Australian mosaic artist Christopher Diaz and is entitled "Australian Spring". If is a wonderful example of how different coloured grouts can enhance your design.