diff --git a/github-linguist.gemspec b/github-linguist.gemspec
index 8f3fe075..3f3a0853 100644
--- a/github-linguist.gemspec
+++ b/github-linguist.gemspec
@@ -23,4 +23,5 @@ Gem::Specification.new do |s|
   s.add_development_dependency 'pry'
   s.add_development_dependency 'rake'
   s.add_development_dependency 'yajl-ruby'
+  s.add_development_dependency 'color-proximity', '~> 0.2.1'
 end
diff --git a/lib/linguist/languages.yml b/lib/linguist/languages.yml
index cf005dfe..01606b9e 100644
--- a/lib/linguist/languages.yml
+++ b/lib/linguist/languages.yml
@@ -46,7 +46,7 @@ AGS Script:
 
 AMPL:
   type: programming
-  color: "#00008B"
+  color: "#E6EFBB"
   extensions:
   - .ampl
   tm_scope: source.ampl
@@ -61,7 +61,7 @@ ANTLR:
 
 APL:
   type: programming
-  color: "#8a0707"
+  color: "#5A8164"
   extensions:
   - .apl
   - .dyalog
@@ -101,7 +101,7 @@ ATS:
 ActionScript:
   type: programming
   tm_scope: source.actionscript.3
-  color: "#e3491a"
+  color: "#882B0F"
   search_term: as3
   aliases:
   - actionscript 3
@@ -125,7 +125,7 @@ Ada:
 
 Agda:
   type: programming
-  color: "#467C91"
+  color: "#315665"
   extensions:
   - .agda
   ace_mode: text
@@ -175,7 +175,7 @@ AppleScript:
 
 Arc:
   type: programming
-  color: "#ca2afe"
+  color: "#aa2afe"
   extensions:
   - .arc
   tm_scope: none
@@ -201,7 +201,7 @@ AsciiDoc:
 
 AspectJ:
   type: programming
-  color: "#1957b0"
+  color: "#a957b0"
   extensions:
   - .aj
   tm_scope: none
@@ -240,7 +240,7 @@ AutoHotkey:
 
 AutoIt:
   type: programming
-  color: "#36699B"
+  color: "#1C3552"
   aliases:
   - au3
   - AutoIt3
@@ -498,14 +498,14 @@ ChucK:
 
 Cirru:
   type: programming
-  color: "#aaaaff"
+  color: "#ccccff"
   ace_mode: cirru
   extensions:
   - .cirru
 
 Clean:
   type: programming
-  color: "#3a81ad"
+  color: "#3F85AF"
   extensions:
   - .icl
   - .dcl
@@ -645,7 +645,7 @@ Creole:
 
 Crystal:
   type: programming
-  color: "#76EEF5"
+  color: "#776791"
   extensions:
   - .cr
   ace_mode: ruby
@@ -705,7 +705,7 @@ D-ObjDump:
 
 DM:
   type: programming
-  color: "#075ff1"
+  color: "#447265"
   extensions:
   - .dm
   aliases:
@@ -737,7 +737,7 @@ Darcs Patch:
 
 Dart:
   type: programming
-  color: "#98BAD6"
+  color: "#00B4AB"
   extensions:
   - .dart
   ace_mode: dart
@@ -772,7 +772,7 @@ Dogescript:
 
 Dylan:
   type: programming
-  color: "#3ebc27"
+  color: "#6c616e"
   extensions:
   - .dylan
   - .dyl
@@ -799,7 +799,7 @@ ECL:
 
 Eagle:
   type: markup
-  color: "#3994bc"
+  color: "#814C05"
   extensions:
   - .sch
   - .brd
@@ -857,7 +857,7 @@ Emacs Lisp:
 
 EmberScript:
   type: programming
-  color: "#f64e3e"
+  color: "#FFF4F3"
   extensions:
   - .em
   - .emberscript
@@ -866,7 +866,7 @@ EmberScript:
 
 Erlang:
   type: programming
-  color: "#0faf8d"
+  color: "#B83998"
   extensions:
   - .erl
   - .es
@@ -895,7 +895,7 @@ F#:
 
 FLUX:
   type: programming
-  color: "#33CCFF"
+  color: "#88ccff"
   extensions:
   - .fx
   - .flux
@@ -1045,7 +1045,7 @@ GLSL:
 
 Game Maker Language:
   type: programming
-  color: "#8ad353"
+  color: "#8fb200"
   extensions:
   - .gml
   tm_scope: source.c++
@@ -1119,7 +1119,7 @@ Go:
 
 Golo:
   type: programming
-  color: "#f6a51f"
+  color: "#88562A"
   extensions:
   - .golo
   tm_scope: source.golo
@@ -1158,7 +1158,7 @@ Grammatical Framework:
   extensions:
   - .gf
   searchable: true
-  color: "#ff0000"
+  color: "#79aa7a"
   tm_scope: source.haskell
   ace_mode: haskell
 
@@ -1326,7 +1326,7 @@ Haxe:
 Hy:
   type: programming
   ace_mode: text
-  color: "#7891b1"
+  color: "#7790B2"
   extensions:
   - .hy
   aliases:
@@ -1335,7 +1335,7 @@ Hy:
 
 IDL:
   type: programming
-  color: "#e3592c"
+  color: "#a3522f"
   extensions:
   - .pro
   - .dlm
@@ -1420,7 +1420,7 @@ Ioke:
 
 Isabelle:
   type: programming
-  color: "#fdcd00"
+  color: "#FEFE00"
   extensions:
   - .thy
   tm_scope: source.isabelle.theory
@@ -1428,7 +1428,7 @@ Isabelle:
 
 J:
   type: programming
-  color: "#2d8abd"
+  color: "#9EEDFF"
   extensions:
   - .ijs
   tm_scope: source.j
@@ -1556,7 +1556,7 @@ Julia:
 
 KRL:
   type: programming
-  color: "#f5c800"
+  color: "#28431f"
   extensions:
   - .krl
   tm_scope: none
@@ -1627,7 +1627,7 @@ LabVIEW:
 
 Lasso:
   type: programming
-  color: "#2584c3"
+  color: "#999999"
   extensions:
   - .lasso
   - .las
@@ -1787,7 +1787,7 @@ M:
 
 MTML:
   type: markup
-  color: "#0095d9"
+  color: "#b7e1f4"
   extensions:
   - .mtml
   tm_scope: text.html.basic
@@ -1882,7 +1882,7 @@ Maven POM:
 
 Max:
   type: programming
-  color: "#ce279c"
+  color: "#c4a79c"
   aliases:
   - max/msp
   - maxmsp
@@ -1906,7 +1906,7 @@ MediaWiki:
 
 Mercury:
   type: programming
-  color: "#abcdef"
+  color: "#ff2b2b"
   ace_mode: prolog
   interpreters:
   - mmi
@@ -1987,14 +1987,14 @@ NSIS:
 
 Nemerle:
   type: programming
-  color: "#0d3c6e"
+  color: "#3d3c6e"
   extensions:
   - .n
   ace_mode: text
 
 NetLinx:
   type: programming
-  color: "#0000ff"
+  color: "#0aa0ff"
   extensions:
   - .axs
   - .axi
@@ -2003,7 +2003,7 @@ NetLinx:
 
 NetLinx+ERB:
   type: programming
-  color: "#407fff"
+  color: "#747faa"
   extensions:
   - .axs.erb
   - .axi.erb
@@ -2012,7 +2012,7 @@ NetLinx+ERB:
 
 NetLogo:
   type: programming
-  color: "#ff2b2b"
+  color: "#ff6375"
   extensions:
   - .nlogo
   tm_scope: source.lisp
@@ -2021,7 +2021,7 @@ NetLogo:
 NewLisp:
   type: programming
   lexer: NewLisp
-  color: "#eedd66"
+  color: "#87AED7"
   extensions:
   - .nl
   - .lisp
@@ -2058,7 +2058,7 @@ Ninja:
 
 Nit:
   type: programming
-  color: "#0d8921"
+  color: "#009917"
   extensions:
   - .nit
   tm_scope: source.nit
@@ -2066,7 +2066,7 @@ Nit:
 
 Nix:
   type: programming
-  color: "#7070ff"
+  color: "#7e7eff"
   extensions:
   - .nix
   aliases:
@@ -2138,7 +2138,7 @@ Objective-C:
 Objective-C++:
   type: programming
   tm_scope: source.objc++
-  color: "#4886FC"
+  color: "#6866fb"
   aliases:
   - obj-c++
   - objc++
@@ -2229,7 +2229,7 @@ Ox:
 
 Oxygene:
   type: programming
-  color: "#5a63a3"
+  color: "#cdd0e3"
   extensions:
   - .oxygene
   tm_scope: none
@@ -2237,7 +2237,7 @@ Oxygene:
 
 Oz:
   type: programming
-  color: "#fcaf3e"
+  color: "#fab738"
   extensions:
   - .oz
   tm_scope: source.oz
@@ -2373,7 +2373,7 @@ Perl:
 
 Perl6:
   type: programming
-  color: "#0298c3"
+  color: "#0000fb"
   extensions:
   - .6pl
   - .6pm
@@ -2403,7 +2403,7 @@ PigLatin:
 
 Pike:
   type: programming
-  color: "#066ab2"
+  color: "#005390"
   extensions:
   - .pike
   - .pmod
@@ -2449,7 +2449,7 @@ PowerShell:
 
 Processing:
   type: programming
-  color: "#2779ab"
+  color: "#0096D8"
   extensions:
   - .pde
   ace_mode: text
@@ -2468,7 +2468,7 @@ Prolog:
 
 Propeller Spin:
   type: programming
-  color: "#2b446d"
+  color: "#7fa2a7"
   extensions:
   - .spin
   tm_scope: source.spin
@@ -2494,7 +2494,7 @@ Public Key:
 
 Puppet:
   type: programming
-  color: "#cc5555"
+  color: "#332A77"
   extensions:
   - .pp
   filenames:
@@ -2520,7 +2520,7 @@ PureBasic:
 
 PureScript:
   type: programming
-  color: "#bcdc53"
+  color: "#1D222D"
   extensions:
   - .purs
   tm_scope: source.haskell
@@ -2529,7 +2529,7 @@ PureScript:
 Python:
   type: programming
   ace_mode: python
-  color: "#3581ba"
+  color: "#3572A5"
   extensions:
   - .py
   - .cgi
@@ -2647,7 +2647,7 @@ RMarkdown:
 
 Racket:
   type: programming
-  color: "#ae17ff"
+  color: "#22228f"
   extensions:
   - .rkt
   - .rktd
@@ -2660,7 +2660,7 @@ Racket:
 
 Ragel in Ruby Host:
   type: programming
-  color: "#ff9c2e"
+  color: "#e17600"
   extensions:
   - .rl
   aliases:
@@ -2791,7 +2791,7 @@ Rust:
 
 SAS:
   type: programming
-  color: "#1E90FF"
+  color: "#B34936"
   extensions:
   - .sas
   tm_scope: source.sas
@@ -2815,7 +2815,7 @@ SPARQL:
 
 SQF:
   type: programming
-  color: "#FFCB1F"
+  color: "#3F3F3F"
   extensions:
   - .sqf
   - .hqf
@@ -2992,7 +2992,7 @@ Slash:
 Slim:
   group: HTML
   type: markup
-  color: "#ff8877"
+  color: "#ff8f77"
   extensions:
   - .slim
   ace_mode: text
@@ -3015,7 +3015,7 @@ Smarty:
 
 SourcePawn:
   type: programming
-  color: "#f69e1d"
+  color: "#5c7611"
   aliases:
   - sourcemod
   extensions:
@@ -3083,7 +3083,7 @@ Swift:
 
 SystemVerilog:
   type: programming
-  color: "#343761"
+  color: "#DAE1C2"
   extensions:
   - .sv
   - .svh
@@ -3208,7 +3208,7 @@ Twig:
 
 TypeScript:
   type: programming
-  color: "#31859c"
+  color: "#2b7489"
   aliases:
   - ts
   extensions:
@@ -3220,7 +3220,7 @@ Unified Parallel C:
   type: programming
   group: C
   ace_mode: c_cpp
-  color: "#755223"
+  color: "#4e3617"
   extensions:
   - .upc
   tm_scope: source.c
@@ -3234,8 +3234,8 @@ UnrealScript:
   ace_mode: java
 
 VCL:
+  group: Perl
   type: programming
-  color: "#0298c3"
   extensions:
   - .vcl
   tm_scope: source.varnish.vcl
@@ -3243,7 +3243,7 @@ VCL:
 
 VHDL:
   type: programming
-  color: "#543978"
+  color: "#adb2cb"
   extensions:
   - .vhdl
   - .vhd
@@ -3257,7 +3257,7 @@ VHDL:
 
 Vala:
   type: programming
-  color: "#ee7d06"
+  color: "#fbe5cd"
   extensions:
   - .vala
   - .vapi
@@ -3265,7 +3265,7 @@ Vala:
 
 Verilog:
   type: programming
-  color: "#848bf3"
+  color: "#b2b7f8"
   extensions:
   - .v
   - .veo
@@ -3273,7 +3273,7 @@ Verilog:
 
 VimL:
   type: programming
-  color: "#199c4b"
+  color: "#199f4b"
   search_term: vim
   aliases:
   - vim
@@ -3309,7 +3309,7 @@ Visual Basic:
 
 Volt:
   type: programming
-  color: "#0098db"
+  color: "#1F1F1F"
   extensions:
   - .volt
   tm_scope: source.d
@@ -3317,7 +3317,7 @@ Volt:
 
 Web Ontology Language:
   type: markup
-  color: "#3994bc"
+  color: "#9cc9dd"
   extensions:
   - .owl
   tm_scope: text.xml
@@ -3433,7 +3433,7 @@ XProc:
 
 XQuery:
   type: programming
-  color: "#2700e2"
+  color: "#5232e7"
   extensions:
   - .xquery
   - .xq
@@ -3516,7 +3516,7 @@ desktop:
 
 eC:
   type: programming
-  color: "#4A4773"
+  color: "#913960"
   search_term: ec
   extensions:
   - .ec
@@ -3548,7 +3548,7 @@ mupad:
 
 nesC:
   type: programming
-  color: "#ffce3b"
+  color: "#94B0C7"
   extensions:
   - .nc
   ace_mode: text
@@ -3581,7 +3581,7 @@ wisp:
 
 xBase:
   type: programming
-  color: "#3a4040"
+  color: "#403a40"
   extensions:
   - .prg
   tm_scope: none
diff --git a/test/helper.rb b/test/helper.rb
index a6a03672..ab3cc8fa 100644
--- a/test/helper.rb
+++ b/test/helper.rb
@@ -2,6 +2,7 @@ require "bundler/setup"
 require "minitest/autorun"
 require "mocha/setup"
 require "linguist"
+require 'color-proximity'
 
 def fixtures_path
   File.expand_path("../fixtures", __FILE__)
diff --git a/test/test_color_proximity.rb b/test/test_color_proximity.rb
new file mode 100644
index 00000000..2356e74a
--- /dev/null
+++ b/test/test_color_proximity.rb
@@ -0,0 +1,23 @@
+require_relative "./helper"
+
+class TestColorProximity < Minitest::Test
+  include Linguist
+
+  def cut_hash(color)
+    color[1..-1] if color.start_with?('#')
+  end
+
+  def test_color_proximity
+    langs_with_colors = Language.all.reject { |language| language.color.nil? }
+    cp = ColorProximity.new(0.05, langs_with_colors.map { |lang| cut_hash(lang.color) })
+    failing_threshold = langs_with_colors.map do |lang|
+      state = cp.past_threshold?(cut_hash(lang.color))
+      if !state.first && lang.color != "##{state.last.first}"
+        "- #{lang} (#{lang.color}) is too close to #{state.last}"
+      end
+    end.compact
+    message = "The following #{failing_threshold.length} languages have failing color thresholds. Please modify the hex color.\n#{failing_threshold.join("\n")}"
+
+    assert failing_threshold.empty?, message
+  end
+end
diff --git a/test/test_language.rb b/test/test_language.rb
index 32eb4341..04525399 100644
--- a/test/test_language.rb
+++ b/test/test_language.rb
@@ -286,9 +286,9 @@ class TestLanguage < Minitest::Test
 
   def test_color
     assert_equal '#701516', Language['Ruby'].color
-    assert_equal '#3581ba', Language['Python'].color
+    assert_equal '#3572A5', Language['Python'].color
     assert_equal '#f1e05a', Language['JavaScript'].color
-    assert_equal '#31859c', Language['TypeScript'].color
+    assert_equal '#2b7489', Language['TypeScript'].color
     assert_equal '#3d9970', Language['LSL'].color
   end