Front garden re-design

We moved house earlier this year and now have a very large rear garden which is a lot of work, so I decided to have the small front garden re-designed to make it a little easier on my back, as i was struggling to keep up with it all. The gardener has reduced the amount of flower beds by putting sleepers in and then gravelling the centre section, which is much better and should be easier to manage. Since this photo I have put a few pots on the gravel with winter pansies and viola, and tulips underneath (lasagne planting), but I'm looking for ideas for plants which I can fill the beds with, which will offer good cover and also great colour throughout the spring/summer (favourite colours are blues/lilacs/pinks). The garden is south-west facing. Any suggestions would be most appreciated.

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Would you prefer shrubs, perennials or a mixture? There are some lovely pink roses in David Austins catalogue, long flowering and scented. Perovskia is shrubby with blue spires, Spirea Anthony Waterer, although quite common, is easy and not too big with pink flowers. Lots of pink, blue and lilac perrenials - geraniums of many sorts, veronicas, perennial salvias, penstemons, phlox, agastache, low growing campanulas in front with prunella grandiflora and dianthus. Type in pink perennials, blue perennials etc on Googleand there will be loads, but perhaps that might be confusing and you would prefer people to name some.
Thanks for your reply, Busy-Lizzie.
I would probably prefer shrubs, as there are 3 rosebushes which were already there, hidden amongst the weeds, which the gardener has grouped together, so we will see how they get on before getting any more. I've noted down all your suggestions, thank you, I will have a google. What time of year is it best to plant shrubs, or does it vary depending on type? I would just like something to give some ground cover as there is far too much soil on show at the moment. Thanks for your help. 
You can plant shrubs now, in fact if they are grown in pots you can plant them anytime, so long as you water them when the weather is warm and dry - especially during the first year. Some more shrubs - pink ones Abelia, Syringa microphylla (but when mature is 6ft tall 10ft wide, smells wonderfull), blue ones - Ceanothus (various sorts), Buddleia (Buzz is a dwarf one), caryopteris. See what your garden centre has and read the labels on the plants.
Erysimums ( perennial wallflowers ) and fuchsias. Both are subshrubs and will provide a long season of colour for very little work.
Thanks to both of you, lots of ideas there, I will have a good google and see what I fancy.
Hi - I would recommend shrubs such as hebes, evergreen grasses and euphorbia (but make sure you dont get the spreading variety - I made that mistake!), box balls etc interspersed with perennials such as oriental poppies (shortish flowering season but spectacular), perennial geraniums, japanese anenomes, penstemon, verbena bonarienses - its what I have in my front garden. Along with bulbs etc, I have something in flower from March until the end of October - I am planning to include more late flowering plants to extend the season further. The shrubs also give evergreen interest throughout the winter.