diff --git a/scss/_custom-forms.scss b/scss/_custom-forms.scss
index 974f764088..c384775daf 100644
--- a/scss/_custom-forms.scss
+++ b/scss/_custom-forms.scss
@@ -12,11 +12,10 @@
 .custom-control {
   position: relative;
   display: inline;
-  padding-left: 1.5rem;
-  color: #555;
+  padding-left: $custom-control-gutter;
 
   + .custom-control {
-    margin-left: 1rem;
+    margin-left: $custom-control-spacer-x;
   }
 }
 
@@ -26,31 +25,31 @@
   opacity: 0;
 
   &:checked ~ .custom-control-indicator {
-    color: #fff;
-    background-color: #0074d9;
-    @include box-shadow(none);
+    color: $custom-control-checked-indicator-color;
+    background-color: $custom-control-checked-indicator-bg;
+    @include box-shadow($custom-control-checked-indicator-box-shadow);
   }
 
   &:focus ~ .custom-control-indicator {
     // the mixin is not used here to make sure there is feedback
-    box-shadow: 0 0 0 .075rem #fff, 0 0 0 .2rem #0074d9;
+    box-shadow: $custom-control-focus-indicator-box-shadow;
   }
 
   &:active ~ .custom-control-indicator {
-    color: #fff;
-    background-color: #84c6ff;
-    @include box-shadow(none);
+    color: $custom-control-active-indicator-color;
+    background-color: $custom-control-active-indicator-bg;
+    @include box-shadow($custom-control-active-indicator-box-shadow);
   }
 
   &:disabled {
     ~ .custom-control-indicator {
-      cursor: not-allowed;
-      background-color: $custom-form-bg-color-disabled;
+      cursor: $custom-control-disabled-cursor;
+      background-color: $custom-control-disabled-indicator-bg;
     }
 
     ~ .custom-control-description {
-      color: $custom-form-description-color-disabled;
-      cursor: not-allowed;
+      color: $custom-control-disabled-description-color;
+      cursor: $custom-control-disabled-cursor;
     }
   }
 }
@@ -64,18 +63,14 @@
   top: .0625rem;
   left: 0;
   display: block;
-  width: 1rem;
-  height: 1rem;
-  font-size: 65%;
-  line-height: 1rem;
-  color: #eee;
-  text-align: center;
+  width: $custom-control-indicator-size;
+  height: $custom-control-indicator-size;
   user-select: none;
-  background-color: $custom-form-bg-color;
+  background-color: $custom-control-indicator-bg;
   background-repeat: no-repeat;
   background-position: center center;
-  background-size: 50% 50%;
-  @include box-shadow(inset 0 .25rem .25rem rgba(0,0,0,.1));
+  background-size: $custom-control-indicator-bg-size;
+  @include box-shadow($custom-control-indicator-box-shadow);
 }
 
 // Checkboxes
@@ -84,17 +79,17 @@
 
 .custom-checkbox {
   .custom-control-indicator {
-    border-radius: .25rem;
+    @include border-radius($custom-checkbox-radius);
   }
 
   .custom-control-input:checked ~ .custom-control-indicator {
-    background-image: url(data:image/svg+xml;base64,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);
+    background-image: url(#{$custom-checkbox-checked-icon});
   }
 
   .custom-control-input:indeterminate ~ .custom-control-indicator {
-    background-color: #0074d9;
-    background-image: url(data:image/svg+xml;base64,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);
-    @include box-shadow(none);
+    background-color: $custom-checkbox-indeterminate-bg;
+    background-image: url(#{$custom-checkbox-indeterminate-icon});
+    @include box-shadow($custom-checkbox-indeterminate-box-shadow);
   }
 }
 
@@ -104,11 +99,11 @@
 
 .custom-radio {
   .custom-control-indicator {
-    border-radius: 50%;
+    border-radius: $custom-radio-radius;
   }
 
   .custom-control-input:checked ~ .custom-control-indicator {
-    background-image: url(data:image/svg+xml;base64,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);
+    background-image: url(#{$custom-radio-checked-icon});
   }
 }
 
@@ -124,7 +119,7 @@
 
     &::after {
       display: block;
-      margin-bottom: .25rem;
+      margin-bottom: $custom-control-spacer-y;
       content: "";
     }
 
@@ -145,23 +140,23 @@
 .custom-select {
   display: inline-block;
   max-width: 100%;
-  padding: .375rem 1.75rem .375rem .75rem;
-  padding-right: .75rem \9;
-  color: $input-color;
+  padding: $custom-select-padding-y ($custom-select-padding-x + $custom-select-indicator-padding) $custom-select-padding-y $custom-select-padding-x;
+  padding-right: $custom-select-padding-x \9;
+  color: $custom-select-color;
   vertical-align: middle;
-  background: #fff url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAUCAMAAACzvE1FAAAADFBMVEUzMzMzMzMzMzMzMzMKAG/3AAAAA3RSTlMAf4C/aSLHAAAAPElEQVR42q3NMQ4AIAgEQTn//2cLdRKppSGzBYwzVXvznNWs8C58CiussPJj8h6NwgorrKRdTvuV9v16Afn0AYFOB7aYAAAAAElFTkSuQmCC) no-repeat right .75rem center;
+  background: $custom-select-bg url(#{$custom-select-indicator}) no-repeat right $custom-select-padding-x center;
   background-image: none \9;
-  background-size: 8px 10px;
-  border: $input-btn-border-width solid $input-border-color;
-  @include border-radius($border-radius);
+  background-size: $custom-select-bg-size;
+  border: $custom-select-border-width solid $custom-select-border-color;
+  @include border-radius($custom-select-border-radius);
   // Use vendor prefixes as `appearance` isn't part of the CSS spec.
   -moz-appearance: none;
   -webkit-appearance: none;
 
   &:focus {
-    border-color: #51a7e8;
+    border-color: $custom-select-focus-border-color;
     outline: none;
-    @include box-shadow(inset 0 1px 2px rgba(0, 0, 0, 0.075), 0 0 5px rgba(81, 167, 232, 0.5));
+    @include box-shadow($custom-select-focus-box-shadow);
   }
 
   // Hides the default caret in IE11
@@ -171,14 +166,14 @@
 }
 
 .custom-select-sm {
-  padding-top: 3px;
-  padding-bottom: 3px;
-  font-size: 12px;
+  padding-top: $custom-select-padding-y;
+  padding-bottom: $custom-select-padding-y;
+  font-size: $custom-select-sm-font-size;
 
-  &:not([multiple]) {
-    height: 26px;
-    min-height: 26px;
-  }
+  // &:not([multiple]) {
+  //   height: 26px;
+  //   min-height: 26px;
+  // }
 }
 
 
diff --git a/scss/_variables.scss b/scss/_variables.scss
index 62515deaac..284e4f7e52 100644
--- a/scss/_variables.scss
+++ b/scss/_variables.scss
@@ -324,10 +324,54 @@ $input-group-addon-border-color: $input-border-color !default;
 
 $cursor-disabled:                not-allowed !default;
 
-$custom-form-bg-color:                    #ddd !default;
-$custom-form-bg-color-disabled:           #eee !default;
-$custom-form-description-color-disabled:  #767676 !default;
+$custom-control-gutter:   1.5rem !default;
+$custom-control-spacer-x: 1rem !default;
+$custom-control-spacer-y: .25rem !default;
 
+$custom-control-indicator-size:       1rem !default;
+$custom-control-indicator-bg:         #ddd !default;
+$custom-control-indicator-bg-size:    50% 50% !default;
+$custom-control-indicator-box-shadow: inset 0 .25rem .25rem rgba(0,0,0,.1) !default;
+
+$custom-control-disabled-cursor:             $cursor-disabled !default;
+$custom-control-disabled-indicator-bg:       #eee !default;
+$custom-control-disabled-description-color:  #767676 !default;
+
+$custom-control-checked-indicator-color:      #fff !default;
+$custom-control-checked-indicator-bg:         #0074d9 !default;
+$custom-control-checked-indicator-box-shadow: none !default;
+
+$custom-control-focus-indicator-box-shadow: 0 0 0 .075rem #fff, 0 0 0 .2rem #0074d9 !default;
+
+$custom-control-active-indicator-color:      #fff !default;
+$custom-control-active-indicator-bg:         #84c6ff !default;
+$custom-control-active-indicator-box-shadow: none !default;
+
+$custom-checkbox-radius: $border-radius !default;
+$custom-checkbox-checked-icon: "data:image/svg+xml;base64,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" !default;
+$custom-checkbox-indeterminate-bg: #0074d9 !default;
+$custom-checkbox-indeterminate-icon: "data:image/svg+xml;base64,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" !default;
+$custom-checkbox-indeterminate-box-shadow: none !default;
+
+$custom-radio-radius: 50% !default;
+$custom-radio-checked-icon: "data:image/svg+xml;base64,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" !default;
+
+$custom-select-padding-x:          .75rem  !default;
+$custom-select-padding-y:          .375rem !default;
+$custom-select-indicator-padding:  1rem !default; // Extra padding to account for the presence of the background-image based indicator
+$custom-select-color:         $input-color !default;
+$custom-select-bg:            #fff !default;
+$custom-select-bg-size:       8px 10px !default; // In pixels because image dimensions
+$custom-select-indicator:     "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAUCAMAAACzvE1FAAAADFBMVEUzMzMzMzMzMzMzMzMKAG/3AAAAA3RSTlMAf4C/aSLHAAAAPElEQVR42q3NMQ4AIAgEQTn//2cLdRKppSGzBYwzVXvznNWs8C58CiussPJj8h6NwgorrKRdTvuV9v16Afn0AYFOB7aYAAAAAElFTkSuQmCC" !default;
+$custom-select-border-width:  $input-btn-border-width !default;
+$custom-select-border-color:  $input-border-color !default;
+$custom-select-border-radius: $border-radius !default;
+
+$custom-select-focus-border-color: #51a7e8 !default;
+$custom-select-focus-box-shadow:   inset 0 1px 2px rgba(0, 0, 0, 0.075), 0 0 5px rgba(81, 167, 232, 0.5) !default;
+
+$custom-select-sm-padding-y: .2rem !default;
+$custom-select-sm-font-size: 75% !default;
 
 // Form validation icons
 $form-icon-success: "data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHZpZXdCb3g9IjAgMCA2MTIgNzkyIj48cGF0aCBmaWxsPSIjNWNiODVjIiBkPSJNMjMzLjggNjEwYy0xMy4zIDAtMjYtNi0zNC0xNi44TDkwLjUgNDQ4LjhDNzYuMyA0MzAgODAgNDAzLjMgOTguOCAzODljMTguOC0xNC4yIDQ1LjUtMTAuNCA1OS44IDguNGw3MiA5NUw0NTEuMyAyNDJjMTIuNS0yMCAzOC44LTI2LjIgNTguOC0xMy43IDIwIDEyLjQgMjYgMzguNyAxMy43IDU4LjhMMjcwIDU5MGMtNy40IDEyLTIwLjIgMTkuNC0zNC4zIDIwaC0yeiIvPjwvc3ZnPg==" !default;