diff --git a/.watchmanconfig b/.watchmanconfig
new file mode 100644
index 0000000..d92d987
--- /dev/null
+++ b/.watchmanconfig
@@ -0,0 +1,6 @@
+{
+  "ignore_dirs": [
+    ".git",
+    "node_modules"
+  ]
+}
diff --git a/src/Interpolation.js b/src/Interpolation.js
index 99f95ca..2a0b1c8 100644
--- a/src/Interpolation.js
+++ b/src/Interpolation.js
@@ -175,20 +175,30 @@ function colorToRgba(input: string): string {
 
 var stringShapeRegex = /[0-9\.-]+/g;
 
+// Covers rgb, rgba, hsl, hsla
+// Taken from https://gist.github.com/olmokramer/82ccce673f86db7cda5e
+var colorRegex = /(#[\d\w]+|\w+\((?:\d+%?(?:,\s)*){3}(?:\d*\.?\d+)?\))/
+// Covers color names (transparent, blue, etc.)
+var colorNamesRegex = new RegExp(`(${Object.keys(normalizeColor.colorNames).join('|')})`, 'g')
+
 /**
  * Supports string shapes by extracting numbers so new values can be computed,
  * and recombines those values into new strings of the same shape.  Supports
  * things like:
  *
- *   rgba(123, 42, 99, 0.36) // colors
- *   -45deg                  // values with units
+ *   rgba(123, 42, 99, 0.36)           // colors
+ *   0 2px 2px 0px rgba(0, 0, 0, 0.12) // box shadows
+ *   -45deg                            // values with units
  */
 function createInterpolationFromStringOutputRange(
   config: InterpolationConfigType,
 ): (input: number) => string {
   var outputRange: Array<string> = (config.outputRange: any);
   invariant(outputRange.length >= 2, 'Bad output range');
-  outputRange = outputRange.map(colorToRgba);
+  // Replace colors with rgba
+  outputRange = outputRange
+    .map(rangeValue => rangeValue.replace(colorRegex, colorToRgba))
+    .map(rangeValue => rangeValue.replace(colorNamesRegex, colorToRgba));
   checkPattern(outputRange);
 
   // ['rgba(0, 100, 200, 0)', 'rgba(50, 150, 250, 0.5)']
@@ -222,19 +232,20 @@ function createInterpolationFromStringOutputRange(
     });
   });
 
-  // rgba requires that the r,g,b are integers.... so we want to round them, but we *dont* want to
-  // round the opacity (4th column).
-  const shouldRound = (/^rgb/).test(outputRange[0]);
-
   return (input) => {
     var i = 0;
-    // 'rgba(0, 100, 200, 0)'
-    // ->
-    // 'rgba(${interpolations[0](input)}, ${interpolations[1](input)}, ...'
-    return outputRange[0].replace(stringShapeRegex, () => {
-      const val = interpolations[i++](input);
-      return String(shouldRound && i < 4 ? Math.round(val) : val);
-    });
+    return outputRange[0]
+      // 'rgba(0, 100, 200, 0)'
+      // ->
+      // 'rgba(${interpolations[0](input)}, ${interpolations[1](input)}, ...'
+      .replace(stringShapeRegex, () => interpolations[i++](input))
+      // rgba requires that the r,g,b are integers.... so we want to round them, but we *dont* want to
+      // round the opacity (4th column).
+      .replace(
+        /rgba\(([0-9\.-]+), ([0-9\.-]+), ([0-9\.-]+), ([0-9\.-]+)\)/gi,
+        (_, p1, p2, p3, p4) =>
+          `rgba(${Math.round(p1)}, ${Math.round(p2)}, ${Math.round(p3)}, ${p4})`
+      )
   };
 }
 
diff --git a/src/normalizeColor.js b/src/normalizeColor.js
index 65018c3..ecf9f0a 100644
--- a/src/normalizeColor.js
+++ b/src/normalizeColor.js
@@ -26,8 +26,8 @@ if ((match = matchers.hex6.exec(color))) {
   return parseInt(match[1] + 'ff', 16) >>> 0;
 }
 
-if (names.hasOwnProperty(color)) {
-  return names[color];
+if (colorNames.hasOwnProperty(color)) {
+  return colorNames[color];
 }
 
 if ((match = matchers.rgb.exec(color))) {
@@ -189,7 +189,7 @@ function parsePercentage(str: string): number {
   return int / 100;
 }
 
-var names = {
+var colorNames = {
   transparent: 0x00000000,
 
   // http://www.w3.org/TR/css3-color/#svg-color
@@ -345,3 +345,4 @@ var names = {
 };
 
 module.exports = normalizeColor;
+module.exports.colorNames = colorNames;