For the most time, I don't care how the diaper look, but it's same as people buying underwear.
I like pink, but I'm not brave enough to wear pink clothes, so I buy pink diapers when I can.
My favorite diaper is Kiddo Playtime, the print is somewhat neutral, but I would have prefered it in pink or white. I buy because it's cheap and the plastic is fantastic.
Sometimes I use a shorter t-shirt than normal so waistband can show, but the thrilling part is that it might show, and that I know it's just a thin t-shirt from being exposed.
People show their underwear and girls show their belly button and underwear...
So in the end, I mostly wear pink or white diapers, and buy only plastic because I like the feel.
6 months of the year they are for my eyes only as there won't be any t-shirt weather.