loading XLS XML file with named colors in ss:Color attribute
See original bug and description here:
The ss:Color attribute should support named colors in addition to the raw RGB values.
Specifies the color of this border. This value can be either a 6-hexadecimal digit number in "#rrggbb" format or it can be any of the Microsoft Internet Explorer named colors (including the named Microsoft Windows colors). This string can also be the special value of "Automatic." This string is case insensitive.
And this page shows possible named colors this attribute may need to support: https://msdn.microsoft.com/en-us/ie/aa358802(v=vs.94)
which is probably equivalent of CSS 3 extended color keywords: https://www.w3.org/TR/css-color-3/#svg-color