T H O U G H T S
A 1-color buzz-kill. The problem is, when you rely so heavily on color to express a concept, and you lay those colors together with nothing to separate them (creating contrast), then when it is translated to 1-color it all runs together (note: outlining the elements of this mark could have been applied for separation, but in this case I am trying to make a point). If the designer had used white strokes to cut through the color sections, more contrast would be there, creating a more recognizable mark (maybe they do have a version like this; I couldn't find one). Now, all you're left with is a run-of-the-mill speech bubble; no distinction. Google is known for their colorful images, but sometimes they ride the color train a little too hard.
R A T I N G S (1-color version)
Scale: Bad, Fair, Good This is all in the context of the 1-color version, not rating the full color version.
Use of Pos/Neg: Bad