[gtk+] docs/css-overview: Fix color functions’ arg orders

[Daniel Boles <dboles src gnome org>]

commit a69083c95efd88ce2796671d983c0fc35891fde5
Author: Daniel Boles <dboles src gnome org>
Date:   Fri Mar 17 23:25:13 2017 +0000

    docs/css-overview: Fix color functions’ arg orders
    
    shade/alpha/mix() take colour(s) and a number that is the ratio by which
    to transform them. It was written here that these shall be passed in the
    order (number, colour). That was wrong: they must be passed in the order
    (colour[s], number) to work, and for the Inspector not to flag an error.

 docs/reference/gtk/css-overview.xml |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/docs/reference/gtk/css-overview.xml b/docs/reference/gtk/css-overview.xml
index 6afa20a..d5e6cf2 100644
--- a/docs/reference/gtk/css-overview.xml
+++ b/docs/reference/gtk/css-overview.xml
@@ -587,7 +587,7 @@ background-color: @bg_color;
       set of base colors.
     </para>
 
-<literallayout><code>〈color expression〉 = lighter(〈color〉) | darker(〈color〉) | shade(〈number〉,〈color〉) | 
alpha(〈number〉,〈color〉) | mix(〈number〉,〈color〉,〈color〉)</code>
+<literallayout><code>〈color expression〉 = lighter(〈color〉) | darker(〈color〉) | shade(〈color〉,〈number〉) | 
alpha(〈color〉,〈number〉) | mix(〈color〉,〈color〉,〈number〉)</code>
 </literallayout>
 
     <para>