After following guidance here and remeasuring myself I've changed bra size from 36c to a 34d/dd. If I wear a plunge bra a D cup is fine, but in a T-shirt bra, I seem to get a better fit from a DD.
I bought a couple of bras in Debenhams - just nude coloured - both plunge, and then also got a nice bright mauve balcony bra (all D cup) for a bit of variety. However, I can't see anything else out there that's what I would call 'interesting'. I just did a quick online search and noted that up to a D cup in t-shirt bras you can have geometric prints, bright turquoise, floral prints, stripes, red, jewel green and pretty much anything bright or patterned. However, cross the line to DD and you get white, beige/nude and black, with the occasional baby pink.
I don't have loads to spend - £20 per bra is going to be my limit. Where can I find something more interesting?