Update _variables-alt.scss

build/scss/_variables-alt.scss

@@ -33,7 +33,7 @@ $grays-alt: map-merge((
 ), $grays-alt);
 
 // Below colors from bootwatch darkly
-$blue-alt:    #375a7f !default;
+$blue-alt:    #3f6791 !default;
 $indigo-alt:  #6610f2 !default;
 $purple-alt:  #6f42c1 !default;
 $pink-alt:    #e83e8c !default;