diff --git a/src/color.js b/src/color.js
index 036d9f4..75d8372 100644
--- a/src/color.js
+++ b/src/color.js
@@ -5,16 +5,9 @@ export function Color() {}
 export var darker = 0.7;
 export var brighter = 1 / darker;
 
-var reI = "\\s*([+-]?\\d+)\\s*",
-    reN = "\\s*([+-]?\\d*\\.?\\d+(?:[eE][+-]?\\d+)?)\\s*",
-    reP = "\\s*([+-]?\\d*\\.?\\d+(?:[eE][+-]?\\d+)?)%\\s*",
-    reHex = /^#([0-9a-f]{3,8})$/,
-    reRgbInteger = new RegExp("^rgb\\(" + [reI, reI, reI] + "\\)$"),
-    reRgbPercent = new RegExp("^rgb\\(" + [reP, reP, reP] + "\\)$"),
-    reRgbaInteger = new RegExp("^rgba\\(" + [reI, reI, reI, reN] + "\\)$"),
-    reRgbaPercent = new RegExp("^rgba\\(" + [reP, reP, reP, reN] + "\\)$"),
-    reHslPercent = new RegExp("^hsl\\(" + [reN, reP, reP] + "\\)$"),
-    reHslaPercent = new RegExp("^hsla\\(" + [reN, reP, reP, reN] + "\\)$");
+var reHex = /^#([0-9a-f]{3,8})$/,
+    reRgb = /^rgb[a]?\(([^)]*)\)$/,
+    reHsl = /^hsl[a]?\(([^)]*)\)$/;
 
 var named = {
   aliceblue: 0xf0f8ff,
@@ -193,6 +186,57 @@ function color_formatRgb() {
   return this.rgb().formatRgb();
 }
 
+function color_isPercent(s) {
+  return s.endsWith("%");
+}
+
+function color_parsePercent(s, k = 1) {
+  return /\d%$/.test(s) ? s.slice(0, -1) * k / 100 : NaN;
+}
+
+function color_parseNumber(s) {
+  return s.endsWith(".") ? NaN : +s;
+}
+
+function color_parseAlpha(s) {
+  return s === undefined ? 1 : (color_isPercent(s) ? color_parsePercent : color_parseNumber)(s);
+}
+
+function color_parseRgb(S) {
+  S = S.split(",").map(s => s.trim());
+  if (S.length < 3 || S.length > 4) return null;
+  let [r, g, b, a] = S;
+  if (color_isPercent(r) || color_isPercent(g) || color_isPercent(g)) {
+    r = color_parsePercent(r, 255);
+    g = color_parsePercent(g, 255);
+    b = color_parsePercent(b, 255);
+  } else {
+    r = color_parseNumber(r);
+    g = color_parseNumber(g);
+    b = color_parseNumber(b);
+  }
+  a = color_parseAlpha(a);
+  if (isNaN(r) || isNaN(g) || isNaN(b) || isNaN(a)) return null;
+  return rgba(r, g, b, a);
+}
+
+function color_parseHsl(S) {
+  S = S.split(",").map(s => s.trim());
+  if (S.length < 3 || S.length > 4) return null;
+  let [h, s, l, a] = S;
+  h = color_parseNumber(h);
+  if (color_isPercent(s) || color_isPercent(l)) {
+    s = color_parsePercent(s);
+    l = color_parsePercent(l);
+  } else {
+    s = color_parseNumber(s);
+    l = color_parseNumber(l);
+  }
+  a = color_parseAlpha(a);
+  if (isNaN(h) || isNaN(s) || isNaN(l) || isNaN(a)) return null;
+  return hsla(h, s, l, a);
+}
+
 export default function color(format) {
   var m, l;
   format = (format + "").trim().toLowerCase();
@@ -201,12 +245,8 @@ export default function color(format) {
       : l === 8 ? rgba(m >> 24 & 0xff, m >> 16 & 0xff, m >> 8 & 0xff, (m & 0xff) / 0xff) // #ff000000
       : l === 4 ? rgba((m >> 12 & 0xf) | (m >> 8 & 0xf0), (m >> 8 & 0xf) | (m >> 4 & 0xf0), (m >> 4 & 0xf) | (m & 0xf0), (((m & 0xf) << 4) | (m & 0xf)) / 0xff) // #f000
       : null) // invalid hex
-      : (m = reRgbInteger.exec(format)) ? new Rgb(m[1], m[2], m[3], 1) // rgb(255, 0, 0)
-      : (m = reRgbPercent.exec(format)) ? new Rgb(m[1] * 255 / 100, m[2] * 255 / 100, m[3] * 255 / 100, 1) // rgb(100%, 0%, 0%)
-      : (m = reRgbaInteger.exec(format)) ? rgba(m[1], m[2], m[3], m[4]) // rgba(255, 0, 0, 1)
-      : (m = reRgbaPercent.exec(format)) ? rgba(m[1] * 255 / 100, m[2] * 255 / 100, m[3] * 255 / 100, m[4]) // rgb(100%, 0%, 0%, 1)
-      : (m = reHslPercent.exec(format)) ? hsla(m[1], m[2] / 100, m[3] / 100, 1) // hsl(120, 50%, 50%)
-      : (m = reHslaPercent.exec(format)) ? hsla(m[1], m[2] / 100, m[3] / 100, m[4]) // hsla(120, 50%, 50%, 1)
+      : (m = reRgb.exec(format)) ? color_parseRgb(m[1]) // rgb(255, 0, 0)
+      : (m = reHsl.exec(format)) ? color_parseHsl(m[1]) // hsl(120, 50%, 50%)
       : named.hasOwnProperty(format) ? rgbn(named[format]) // eslint-disable-line no-prototype-builtins
       : format === "transparent" ? new Rgb(NaN, NaN, NaN, 0)
       : null;
diff --git a/test/color-test.js b/test/color-test.js
index 2c44313..95ade59 100644
--- a/test/color-test.js
+++ b/test/color-test.js
@@ -127,8 +127,8 @@ tape("color(format) allows exponential format for hue, opacity and percentages",
   test.end();
 });
 
-tape("color(format) does not allow decimals for integer values", function(test) {
-  test.equal(color.color("rgb(120.5,30,50)"), null);
+tape("color(format) allows decimals for integer values", function(test) {
+  test.rgbEqual(color.color("rgb(120.5,30,50)"), 120.5, 30, 50, 1);
   test.end();
 });