[gegl] gegl-color: Add documentation about format of accepted strings

[Jon Nordby <jonnor src gnome org>]

commit 3121b9cf88f8dcfc614a1e15f5854d90d777763d
Author: Jon Nordby <jononor gmail com>
Date:   Wed Aug 6 17:07:38 2014 +0200

    gegl-color: Add documentation about format of accepted strings

 gegl/property-types/gegl-color.h |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)
---
diff --git a/gegl/property-types/gegl-color.h b/gegl/property-types/gegl-color.h
index ab52d96..7d5480d 100644
--- a/gegl/property-types/gegl-color.h
+++ b/gegl/property-types/gegl-color.h
@@ -53,6 +53,15 @@ GType        gegl_color_get_type               (void) G_GNUC_CONST;
  * GeglColor is an object containing a color at the moment only RGB colors
  * are supported, in the future a GeglColor might also indicate other
  * enumerated or natively in other color representations colors.
+ *
+ * GeglColor accepts a subset of format string as defined by the CSS color specification:
+ *  http://dev.w3.org/csswg/css-color/
+ *
+ * - RGB hexadecimal notation: #rrggbb[aa] / #rgb[a]
+ * - Named colors, limited to the 16 specified in HTML4
+ * 
+ * To specify linear-light floating-point RGB, use: rgb[a](0.40, 0.44, 0.92 [, a])
+ * The normal bounds are [0.0 1.0], unlike CSS which is [0 255]. Out-of-bounds values are allowed.
  */
 
 /**