teasing out an ars poetica

I'm curious why poetry has to be in black and white. has to be? at least in a traditional sense. I am curious why all poems printed today are in black and white (save a few), but this is a dominant way that poetry is written. does adding color cause a sudden diversion from poetry enough that it is not accepted by the wider poetry field as poetry? does it become art at that point. 

josh bell, in his poetry collection "no planets strike" includes a long description, at the end of his collection, of the font his poems are set in. I am not sure if he wrote this, but I would hazard to guess that he did. such attention to the font is interesting to say the least. but it means that the font choice is a conscious one, but why stop the consciousness of only font and cover and the other aspects of the poetry collection or poem.

specifically color. specifically handwriting. specifically flat paper. specifically paper.