Kitchens to me should be warm and nurturing, a place where friends and family gather and where you can express creativity, colour can enhance the space allowing you to be inspired and energized.
If you want to bring some colour into your kitchen and do not want to repaint, re-tile or change the units think about bringing colour in by maybe displaying coloured bottles on a window sill, I use sun catcher’s in my windows they bounce the most amazing coloured rainbows around the room.
Display coloured plates, bowels, jugs, cooking books, whatever looks good on an open shelve or on a wall. Fresh cut flowers, bunches of dried flowers and herbs, all add colour and texture. Add a colourful rug or change the window treatments, all of these things do not cost much and have some fun with it.