MapColor.FromName() allows unrecognized colors to be entered

[MaximillianC]

Per the following, the static maps API only accepts 10 different named colors. The MapColor.FromName() method allows you to enter any color name string, and the parameter name (cssColor) is a bit misleading, as not all CSS colors are acceptable. I suggest using an enum for this, instead.

color: (optional) specifies a 24-bit color (example: color=0xFFFFCC) or a predefined color from the set {black, brown, green, purple, yellow, blue, gray, orange, red, white}.