To get colour in your garden add winter flowering plants such as hellebores which are the best of all winter flowering herbaceous plants. Plant in a shaded area with snowdrops and Ires reticulate cultivars, they create a wonderful sight in your garden.
Other ways of creating colour is with bark and stems of trees and shrubs, examples of these are white barked birches such as betula utilis var. and the Tibetan cherry prunus serrula which has cinnamon coloured bark. All with peeling bark will enhance your winter garden.