--- a/Libs/DF/button.lua	Fri Jun 26 14:03:10 2015 -0300
+++ b/Libs/DF/button.lua	Sat Jul 18 17:32:30 2015 -0300
@@ -988,11 +988,13 @@
 end
 
 local pickcolor_callback = function (self, r, g, b, a, button)
+	a = abs (a-1)
 	button.MyObject.color_texture:SetVertexColor (r, g, b, a)
 	button.MyObject:color_callback (r, g, b, a)
 end
-local pickcolor = function (alpha, param2, self)
+local pickcolor = function (self, alpha, param2)
 	local r, g, b, a = self.MyObject.color_texture:GetVertexColor()
+	a = abs (a-1)
 	DF:ColorPick (self, r, g, b, a, pickcolor_callback)
 end
 
@@ -1000,6 +1002,7 @@
 local color_button_width = 16
 
 local set_colorpick_color = function (button, r, g, b, a)
+	a = a or 1
 	button.color_texture:SetVertexColor (r, g, b, a)
 end