We Grouted this SHOWER and IT LOOKS BAD!!! --- Inconsistent DARK and LIGHT Spots

One of the issues we have with grout is that it can dry with inconsistent color shading with some areas lighter or darker. Since it is a cement product with acrylic polymers and color pigment, many factors can attribute to the color that ultimately dries to. What kind of water is used, drying time, humidity, and application can all lead to inconsistent color and shading of the grout.
On this project we used Custom Building Products Polyblend Plus non sanded grout and it came out bad. The only thing we could do to fix it is scrape it out, and re-grout it.