(Click on large picture above for an even larger view.)
Here is a set of four4 contemporary Fiesta Coffee Mugs. They are in the lighter (retired?) blue and all have the Fiesta hallmark on the bottom with the HL (Homer Laughlin) mark.
They measure 3-1/2" tall and the opening at the mouth is 3-1/2" and hold 10-1/4 OZ of liquid.
My daughter bought several sets of this blue and the yellow and didn't need/want that many mugs so they have never been used and all are in perfect condition