Grout is no longer limited to white or other light colours. Many homeowners are using darker-coloured grouts to emphasise the geometric patterns and colours of tile layouts on walls and floors. Although dark-coloured grout may mask stains better than lighter colours, its porous surface soon accumulates dirt, dust and grime. While coloured grout is similar to white grout, cleaning techniques differ, since common cleaning solutions may discolour coloured grout. Frequently cleaning coloured grout with supplies tailored for use on coloured grout effectively removes grime and stains.
Pour 1 cup of oxygen bleach powder into a mop bucket. Add 1 gallon of water to the oxygen bleach. Unlike chlorine bleach, oxygen bleach is non-toxic and does not discolour coloured grouts.
Fill a spray bottle with the solution. Spray the solution liberally over the coloured grout.
Allow the grout to absorb the solution for 45 minutes. If the grout begins to dry during that period of time, spray it again with the solution. Keep the grout wet during the entire dwell, or soaking, period.
Scrub the grout lightly with a grout brush, once the dwell period is over. Mop up the dirty solution with a sponge mop.
Rinse out the mop bucket and sponge mop. Fill the mop bucket with plain water.
Mop the grout with the water, using the sponge mop. Immediately wipe the grout and nearby tiles with a clean towel.
You can substitute a toothbrush for the grout brush.
Never clean coloured grout with chlorine bleach; this can strip it of colour.