Greenery is all very well but I like to see swathes of colourful flowers.
I try to envisage how mixed planting will shape up in terms of colour but generally my minds eye falls short when it comes to the imagination department.
The best tip is to keep it simple with only a very limited number of varieties chosen because they are due to flower around the same time.

By contrast my wife, on the other hand, is wedded to green leafed houseplants, green conservatory plants and even green outdoors. (She is also wedded to me and I am not as green as I am cabbage looking so at least I get some colour into the garden)
Perhaps she should grow Gloxinia

I do not mind seeing my colour in wild meadows or just as yellow in a field of buttercups. This photo looks like a pointillist painting rather than a snap shot but it was planned by RHS gardeners to look something like this when the ground was laid out.

A friend at our village gardeners club insists she only grows flowers that avoid yellow – I guess she thinks it too garish and she misses out on some grand flowers.

Woodland walks in Spring would not be the same if it wasn’t for the Snowdrops, Aconites and Narcissus.
Even wild garlic is better when you can see the white flower.
Is white really a colour some folk ask – to me a resounding yes, just consider a rainbow.