Index: node_modules/d3-interpolate/src/rgb.js
===================================================================
--- node_modules/d3-interpolate/src/rgb.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-interpolate/src/rgb.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,55 @@
+import {rgb as colorRgb} from "d3-color";
+import basis from "./basis.js";
+import basisClosed from "./basisClosed.js";
+import nogamma, {gamma} from "./color.js";
+
+export default (function rgbGamma(y) {
+  var color = gamma(y);
+
+  function rgb(start, end) {
+    var r = color((start = colorRgb(start)).r, (end = colorRgb(end)).r),
+        g = color(start.g, end.g),
+        b = color(start.b, end.b),
+        opacity = nogamma(start.opacity, end.opacity);
+    return function(t) {
+      start.r = r(t);
+      start.g = g(t);
+      start.b = b(t);
+      start.opacity = opacity(t);
+      return start + "";
+    };
+  }
+
+  rgb.gamma = rgbGamma;
+
+  return rgb;
+})(1);
+
+function rgbSpline(spline) {
+  return function(colors) {
+    var n = colors.length,
+        r = new Array(n),
+        g = new Array(n),
+        b = new Array(n),
+        i, color;
+    for (i = 0; i < n; ++i) {
+      color = colorRgb(colors[i]);
+      r[i] = color.r || 0;
+      g[i] = color.g || 0;
+      b[i] = color.b || 0;
+    }
+    r = spline(r);
+    g = spline(g);
+    b = spline(b);
+    color.opacity = 1;
+    return function(t) {
+      color.r = r(t);
+      color.g = g(t);
+      color.b = b(t);
+      return color + "";
+    };
+  };
+}
+
+export var rgbBasis = rgbSpline(basis);
+export var rgbBasisClosed = rgbSpline(basisClosed);