Pitchers Glove - all one color?

[TFig27]

I thought it was a rule that a pitcher's glove must be all one color. Is this so?

The only rules for a pitcher's glove that I was able to find was:

1.15
(a) The pitcher’s glove may not, exclusive of piping, be white, gray, nor, in the judgment of an umpire, distracting in any manner.
(b) No pitcher shall attach to his glove any foreign material of a color different from the glove.
(c) The umpire-in-chief shall cause a glove that violates Rules 1.15(a) or 1.15(b) to be removed from the game, either on his own initiative, at the recommendation of another umpire or upon complaint of the opposing manager that the umpire-in-chief agrees has merit.

[GarkoCollector]

That rule is rarely enforced unless its flat out distracting like the Fluorescent Orange one Jose Lima tried to use that looked like a Construction Worker's Vest.