From 4af3ac7faecea98bd2595daeac30a9698099abaa Mon Sep 17 00:00:00 2001
From: Audrey <audrey.kuo@gmail.com>
Date: Tue, 13 May 2014 16:43:52 -0400
Subject: [PATCH] Update d3.d.ts

Gamma value k is optional per https://github.com/mbostock/d3/wiki/Colors
---
 d3/d3.d.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/d3/d3.d.ts b/d3/d3.d.ts
index 42f94d0c6..f6f3f9d04 100644
--- a/d3/d3.d.ts
+++ b/d3/d3.d.ts
@@ -1463,7 +1463,7 @@ declare module D3 {
             /**
             * decrease lightness by some exponential factor (gamma)
             */
-            darker(k: number): Color;
+            darker(k?: number): Color;
             /**
             * convert the color to a string.
             */