Make color a type.

stepmania/Docs/Lua.xsl

@@ -310,6 +310,7 @@
 				$type='string' or
 				$type='bool' or
 				$type='table' or
+				$type='color' or
 				$type='Enum'">
 			<span class="primitiveType">
 				<xsl:value-of select="$type" />

stepmania/Docs/LuaDocumentation.xml

@@ -207,6 +207,9 @@
 	<Function name='cullmode' return='void' arguments='CullMode mode'>
 		Sets the Actor's cull mode to <code>mode</code>.
 	</Function>
+	<Function name='diffuse' return='void' arguments='color c'>
+		Set the Actor's diffuse color to <code>c</code>.
+	</Function>
 	<Function name='diffusealpha' return='void' arguments='float fAlpha'>
 		Set's the Actor's alpha level to <code>fAlpha</code>, where <code>fAlpha</code> is in the range 0..1.
 	</Function>