[LyX/master] In mathed, require xcolor instead of color when appropriate

[Enrico Forestieri]

commit ccc0e03fdc4c880685db016d97cdea802512d104
Author: Enrico Forestieri <for...@lyx.org>
Date:   Wed Oct 5 01:18:15 2016 +0200

    In mathed, require xcolor instead of color when appropriate
    
    Fixes bug #10417.
---
 src/mathed/InsetMathColor.cpp |   20 ++++++++++++++++++--
 1 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/src/mathed/InsetMathColor.cpp b/src/mathed/InsetMathColor.cpp
index c50f613..cbf6cb5 100644
--- a/src/mathed/InsetMathColor.cpp
+++ b/src/mathed/InsetMathColor.cpp
@@ -74,8 +74,24 @@ static bool normalcolor(docstring const & color)
 void InsetMathColor::validate(LaTeXFeatures & features) const
 {
        InsetMathNest::validate(features);
-       if (!normalcolor(color_))
-               features.require("color");
+       if (!normalcolor(color_)) {
+               switch (lcolor.getFromLaTeXName(to_utf8(color_))) {
+                       case Color_brown:
+                       case Color_darkgray:
+                       case Color_gray:
+                       case Color_lightgray:
+                       case Color_lime:
+                       case Color_olive:
+                       case Color_orange:
+                       case Color_pink:
+                       case Color_purple:
+                       case Color_teal:
+                       case Color_violet:
+                               features.require("xcolor");
+                       default:
+                               features.require("color");
+               }
+       }
 }