Ideas for flowers in my raised beds.

Hi All, sorry, second post in less than an hour! Just trying to get everything done in the garden now I have some time off and have lots of questions so apologies in advance for the many questions!
Ok so at the front of my property I have some raised beds which look a complete mess...
What I would like to plant is some nice bushy flowery plants that will at least retain some green in the winter and not die completely off. I have problems with kids using my front walls as a social gathering area during the school hols so the bushier the better really!
I love colour so the brighter/colourful the better - apologies if im asking the impossible here!
Its quite exposed so I guess nothing too delicate would be advantageous.
I literally have zero clue when it comes to gardening so any suggestions would be greatly appreciated!
Posts
I find wallflowers to be good value; typically, in full sun, flower from April through til' November, and during very mild winters can actually stay flowering all year round. They don't really lose their leaves and generally won't grow too big for the tub/bed they're in- low maintenance (needs occasional haircut). As an added bonus the yellow ones smell gorgeous!
Lithodora "Heavenly Blue" is very nice too although it can get a bit straggly over time (although I never do anything to mine and it still looks great).
Might be a good idea to include some dwarf Berberis. You can get them with green, red or gold foliage. Though they are deciduous, they are also very prickly, so may make your wall less popular with the youth of the area