Colour can just as easily come from leaves, stems or fruits as it can from flowers. Foliage colour is particularly important as it is present in the garden for much longer than the shades of transitory blooms. Use variegated foliage sparingly and wisely. One variegated specimen, such as Elaeagnus pungens 'Maculata', will look stunning surrounded by plain green shrubs. If it was planted, however, with other variegated plants it would lose its emphasis and the whole picture would appear too busy.
Colours can either contrast or harmonise.
Harmonising colours are close together in the spectrum - blues, pinks and purples or yellow, oranges and reds. Contrasting colours are green and red, blue and yellow or purple and orange. Colours can be affected by the quantities used and the diluting effect of green foliage. For example, a few self-seeded orange marigolds around the base of a pink Lavatera can look attractive, because the foliage of the Lavatera acts as a buffer between the pink and the orange. On the other hand, neighbouring blocks of pink petunias and orange marigolds will have you reaching for the sunglasses.