diff --git a/package-lock.json b/package-lock.json
index 1435410..65a7536 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@kurkle/color",
-  "version": "0.2.0",
+  "version": "0.2.1",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "@kurkle/color",
-      "version": "0.2.0",
+      "version": "0.2.1",
       "license": "MIT",
       "devDependencies": {
         "assert": "^2.0.0",
diff --git a/package.json b/package.json
index 97a2168..c77fe98 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@kurkle/color",
-  "version": "0.2.0",
+  "version": "0.2.1",
   "description": "css color parsing, manupulation and conversion",
   "main": "dist/color.js",
   "module": "dist/color.esm.js",
diff --git a/src/color.js b/src/color.js
index cb7cedd..7b7aa3c 100644
--- a/src/color.js
+++ b/src/color.js
@@ -7,7 +7,7 @@ import {b2n, n2b, round} from './byte';
 import {hexParse, hexString} from './hex';
 import {hsl2rgb, hslString, hueParse, rgb2hsl, rotate} from './hue';
 import {nameParse} from './names';
-import {rgbMix, rgbParse, rgbString} from './rgb';
+import {rgbParse, rgbString} from './rgb';
 import {interpolate} from './srgb';
 
 /**
@@ -156,7 +156,19 @@ export default class Color {
    */
   mix(color, weight) {
     if (color) {
-      rgbMix(this._rgb, color._rgb, weight);
+      const c1 = this.rgb;
+      const c2 = color.rgb;
+      let w2; // using instead of undefined in the next line
+      const p = weight === w2 ? 0.5 : weight;
+      const w = 2 * p - 1;
+      const a = c1.a - c2.a;
+      const w1 = ((w * a === -1 ? w : (w + a) / (1 + w * a)) + 1) / 2.0;
+      w2 = 1 - w1;
+      c1.r = 0xFF & w1 * c1.r + w2 * c2.r + 0.5;
+      c1.g = 0xFF & w1 * c1.g + w2 * c2.g + 0.5;
+      c1.b = 0xFF & w1 * c1.b + w2 * c2.b + 0.5;
+      c1.a = p * c1.a + (1 - p) * c2.a;
+      this.rgb = c1;
     }
     return this;
   }
diff --git a/src/rgb.js b/src/rgb.js
index 09c86b0..107a31b 100644
--- a/src/rgb.js
+++ b/src/rgb.js
@@ -60,17 +60,3 @@ export function rgbString(v) {
       : `rgb(${v.r}, ${v.g}, ${v.b})`
   );
 }
-
-/**
- * Mix rgb2 to rgb1 by percent ratio (in place).
- * @param {RGBA} rgb1 - the color (also the return value)
- * @param {RGBA} rgb2 - the mixed color
- * @param {number} t - 0..1 (default 0.5)
- */
-export function rgbMix(rgb1, rgb2, t = 0.5) {
-  t = 1 - t;
-  rgb1.r = 0xFF & rgb1.r + t * (rgb2.r - rgb1.r) + 0.5;
-  rgb1.g = 0xFF & rgb1.g + t * (rgb2.g - rgb1.g) + 0.5;
-  rgb1.b = 0xFF & rgb1.b + t * (rgb2.b - rgb1.b) + 0.5;
-  rgb1.a = rgb1.a + t * (rgb2.a - rgb1.a);
-}