diff --git a/utils/color.lua b/utils/color.lua
index 53e7a72..dec0d13 100644
--- a/utils/color.lua
+++ b/utils/color.lua
@@ -23,7 +23,7 @@ function rgbToHsl(r, g, b, a)
     h, s = 0, 0 -- achromatic
   else
     local d = max - min
-    local s
+    --local s   -- <- FIXED: 's' should not be declared here as local.
     if l > 0.5 then s = d / (2 - max - min) else s = d / (max + min) end
     if max == r then
       h = (g - b) / d