Everything goes with everything - especially pink!
In the bold and brilliant garden, clashes of colour don't really happen. All the bold and brilliant colours tend to go well with each other. Discretion is required though in how large to make your clumps of colour. You want to avoid a mimsy-pimsy, traditional-municipal-garden arrangement of having lots of little plants each in a different bold colour. Instead you want to promote solid blocks of colour. In the picture below I have a decent-sized clump of Alstroemeria 'Indian Summer' giving me the hot colours of orange/red/yellow, and below it a contrasting solid line of five bright pink pelargoniums (survivors, pleasingly, from the previous year). This combination looks great. and will continue to look great into the late autumn. The surrounding plants tend to echo the arrangement - for instance the foliage plant to the right of the alstroe is Eucomis Comosa 'Sparkling Burgundy' which underlines the alstroe's dark foliage, whereas the yellow evergreen shrub...