the u87 aint really a dark mic, it's a mic with an edge in the upper mids. It's just darker than ultra bright mics a la c800g. (note I did use the u87 on numerous occasions, never tried the c800g, I'm just repeating what I've been reading here and there, in my experience the u87 is far from dark)
here's a feq response curve for the u87
GR pres are meant to be nice "neveish" pres, I would rather add a nice valve compressor to that chain and nice AD instead of another pre.