diff --git a/_sass/_theme-colors.scss b/_sass/_theme-colors.scss
index 51f1313..0967886 100644
--- a/_sass/_theme-colors.scss
+++ b/_sass/_theme-colors.scss
@@ -116,7 +116,7 @@ $_luminance-list: .0008 .001 .0011 .0013 .0015 .0017 .002 .0022 .0025 .0027 .003
 }
 // Return opaque color
 @function opaque($background, $foreground) {
-    @return mix(rgba($foreground, 1), $background, opacity($foreground) * 100);
+    @return mix(rgba($foreground, 1), $background, opacity($foreground) * 100%);
 }
 // Return WCAG2.0 relative luminance
 @function luminance($color) {