fix(contrast threshold): 4.5 instead of 3

scss/_variables.scss

@@ -95,7 +95,7 @@ $theme-colors: map-merge(
 $theme-color-interval: 8% !default;
 
 // The yiq lightness value that determines when the lightness of color changes from "dark" to "light". Acceptable values are between 0 and 255.
-$yiq-contrasted-threshold: 3 !default;
+$yiq-contrasted-threshold: 4.5 !default;
 
 // Customize the light and dark text colors for use in our YIQ color contrast function.
 $yiq-text-dark: $gray-900 !default;