diff --git a/src/lib/isRgbColor.js b/src/lib/isRgbColor.js
index 0229b41c2..c543fe5ec 100644
--- a/src/lib/isRgbColor.js
+++ b/src/lib/isRgbColor.js
@@ -4,6 +4,7 @@ const rgbColor = /^rgb\((([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5]),){2}
 const rgbaColor = /^rgba\((([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5]),){3}(0?\.\d|1(\.0)?|0(\.0)?)\)$/;
 const rgbColorPercent = /^rgb\((([0-9]%|[1-9][0-9]%|100%),){2}([0-9]%|[1-9][0-9]%|100%)\)/;
 const rgbaColorPercent = /^rgba\((([0-9]%|[1-9][0-9]%|100%),){3}(0?\.\d|1(\.0)?|0(\.0)?)\)/;
+const startsWithRgb = /^rgba?/;
 
 export default function isRgbColor(str, includePercentValues = true) {
   assertString(str);
@@ -14,8 +15,8 @@ export default function isRgbColor(str, includePercentValues = true) {
     return rgbColor.test(strippedStr) || rgbaColor.test(strippedStr);
   }
 
-  return rgbColor.test(strippedStr) ||
+  return startsWithRgb.test(str) && (rgbColor.test(strippedStr) ||
     rgbaColor.test(strippedStr) ||
     rgbColorPercent.test(strippedStr) ||
-    rgbaColorPercent.test(strippedStr);
+    rgbaColorPercent.test(strippedStr));
 }
diff --git a/test/validators.js b/test/validators.js
index d008ee244..08f106b89 100644
--- a/test/validators.js
+++ b/test/validators.js
@@ -4278,6 +4278,7 @@ describe('Validators', () => {
         'rgba(5%,5%,5%,.3)',
         'rgb( 255,255 ,255)',
         'rgba(255, 255, 255, 0.5)',
+        'rgba(255, 255, 255, 0.5)',
       ],
       invalid: [
         'rgb(0,0,0,)',
@@ -4293,6 +4294,8 @@ describe('Validators', () => {
         'rgba(3,3,3%,.3)',
         'rgb(101%,101%,101%)',
         'rgba(3%,3%,101%,0.3)',
+        'r         g    b(   0,         251,       222     )',
+        'r         g    ba(   0,         251,       222     )',
       ],
     });