I wear black almost all the time.  Not plain black - black with patterns!  black paired with another color! - but lots of black regardless.  It started in college when I was doing lots of plays, continued through my stint in professional theatre (you have to wear all black while doing stage management things so you cannot be seen; this includes shoes and often, for me anyway, a hat because my hair is a bright color).  Thereafter, it just stuck.

Plus, I look nice in black, partially because my hair is a bright color.

But it's still summer, and I've found that almost all of my nice work-ish outfits are mostly, or at least half, black.

Too late really, soon it will be too cool to wear summery outfits anyway and everyone will be back to wearing black all the time.  But I might look a little weird for another week or two.