diff --git a/Zframework/color.lua b/Zframework/color.lua
index 73b5afae..a163f46a 100644
--- a/Zframework/color.lua
+++ b/Zframework/color.lua
@@ -1,6 +1,6 @@
 local abs=math.abs
 local function hsv(h,s,v,a)
-    if s<=0 then return v,v,v end
+    if s<=0 then return v,v,v,a end
     h=h*6
     local c=v*s
     local x=abs((h-1)%2-1)*c