diff --git a/src/components/FontAwesomeIcon/scss/_variables.scss b/src/components/FontAwesomeIcon/scss/_variables.scss
index 23cce38..9959231 100644
--- a/src/components/FontAwesomeIcon/scss/_variables.scss
+++ b/src/components/FontAwesomeIcon/scss/_variables.scss
@@ -48,6 +48,11 @@ $fa-stack-z-index       : auto !default;
 $fa-font-display        : block !default;
 $fa-font-path           : "./webfonts" !default;
 
+$fa-primary-color       : inherit !default;
+$fa-primary-opacity     : 1 !default;
+$fa-secondary-opacity   : 4 !default;
+$fa-secondary-color     : inherit !default;
+
 $fa-var-0: \30;
 $fa-var-1: \31;
 $fa-var-2: \32;
diff --git a/src/components/FontAwesomeIcon/scss/duotone.scss b/src/components/FontAwesomeIcon/scss/duotone.scss
index 1b17358..fc89b88 100644
--- a/src/components/FontAwesomeIcon/scss/duotone.scss
+++ b/src/components/FontAwesomeIcon/scss/duotone.scss
@@ -28,8 +28,8 @@
 .fad:before,
 .#{$fa-css-prefix}-duotone:before{
   position: absolute;
-  color: var(--fa-primary-color,inherit);
-  opacity: var(--fa-primary-opacity,1);
+  color: $fa-primary-color;
+  opacity: $fa-primary-opacity;
 }
 
 .#{$fa-css-prefix}-duotone.#{$fa-css-prefix}-swap-opacity:before, 
@@ -38,9 +38,9 @@
 .fad:before, 
 .fad.#{$fa-css-prefix}-swap-opacity:before, 
 .fad:after {
-  opacity: var(--fa-secondary-opacity,.4);
+  opacity: $fa-secondary-opacity;
 }
 
 .#{$fa-css-prefix}-duotone:after, .fad:after {
-  color: var(--fa-secondary-color,inherit);
+  color: $fa-secondary-color;
 }
\ No newline at end of file