diff --git a/README.MD b/README.MD
index 2114dad..fb1e723 100644
--- a/README.MD
+++ b/README.MD
@@ -288,6 +288,15 @@ v.ValidationMessageValidCssClassName   = 'valid-feedback';             // change
 v.bootstrap();
 ```
 
+## Customizing highlight and unhighlight functions
+
+```js
+var v = new aspnetValidation.ValidationService();
+v.highlight = function (input, errorClass, validClass) { ... };
+v.unhighlight = function (input, errorClass, validClass) { ... };
+v.bootstrap();
+```
+
 ## Logging
 
 There is a rudimentary logging infrastructure in place if you want to get more insight into what the library is doing.
diff --git a/src/index.ts b/src/index.ts
index ad1a309..e3472b7 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1252,7 +1252,7 @@ export class ValidationService {
             }
         }
 
-        this.swapClasses(input,
+        this.highlight(input,
             this.ValidationInputCssClassName,
             this.ValidationInputValidCssClassName);
 
@@ -1287,9 +1287,9 @@ export class ValidationService {
             }
         }
 
-        this.swapClasses(input,
-            this.ValidationInputValidCssClassName,
-            this.ValidationInputCssClassName);
+        this.unhighlight(input,
+            this.ValidationInputCssClassName,
+            this.ValidationInputValidCssClassName);
 
         // Removing an error from one input should also remove it from others with the same name (i.e. for radio button and checkbox lists).
         if (input.form) {
@@ -1513,6 +1513,26 @@ export class ValidationService {
         }
     }
 
+    /**
+     * Highlights invalid element by adding errorClass CSS class and removing validClass CSS class
+     * @param input Element to modify
+     * @param errorClass Class to add
+     * @param validClass Class to remove
+     */
+    highlight(input : ValidatableElement, errorClass: string, validClass: string) {
+        this.swapClasses(input, errorClass, validClass);
+    }
+
+    /**
+     * Unhighlight valid element by removing errorClass CSS class and adding validClass CSS class
+     * @param input Element to modify
+     * @param errorClass Class to remove
+     * @param validClass Class to add
+     */
+    unhighlight(input: ValidatableElement, errorClass: string, validClass: string) {
+        this.swapClasses(input, validClass, errorClass);
+    }
+
     /**
      * Override CSS class name for input validation error. Default: 'input-validation-error'
      */