chimchar - yes! my entire wardrobe is made up of grey, black, navy & white, with a little bit of khaki green for whenever I'm feeling especially daring 
I'm happy enough with the overall style but it's all a bit predictable (skinnies, ankle boots, wedge trainers, converse, tube skirts, tea dresses, coloured tights, knee boots, ballet pumps, chunky jumpers, sweatshirts, hoodies, Breton tops, parka, a million scarves, blah blah blah).
I think the problem is that I like wearing all of these but tend to go for the safe options of each of them (grey! navy!) instead of breaking out and trying something a bit unexpected and eye-catching. I kind of look like I'm wearing the uniform of the 40something woman who shops in Zara... then I see someone wearing a fabulous pair of bright yellow shoes and think why can't I bring myself to buy something like that instead of the inevitable black ones.