Color Go Server – CGS

Color Go Server, or CGS, is an Internet Go server enabling you to play against other players, worldwide, in real time and directly from your browser. Its main purpose is to facilitate Go (game) discovery and learning, by updating its design and by adding some tools making the rules easier to understand.

We are proud to announce you that you will be able to play on Color Go Server on January 23, 2021 6:00 PM CET (Paris)

Directly from your web browser at

Why CGS ?

Go is an fascinating game which has been played for almost 3000 years. This seniority is a mark of quality. Still, it is a difficult game for beginners to grasp, which prevents them from capturing its depth and beauty.

However, the basic rules are extremely easy and can be learned within 5 minutes … But the final goal, to control a bigger territory than his opponent, remains hard for beginners to visualize.

This is why CGS’s purpose is to help new players learning the game rules in a more intuitive way.

Helping beginners


CGS stands out with its unique game board display. Players slide from a sober board with black and white stones to a colorful board where each territories take shape in real time.

With its attractive design, CGS could pique the curiosity of new Go players.


The game main objective, to control a territory, is hard for beginners to visualize.

On CGS, beginners will be able to intuitively understand how a territory is built or modified by instantly visualizing the impact of every move.


In a game of Go, each stone has a certain influence on the board. This is very hard for a beginner to visualize on a traditional board. CGS points out territories by highlighting this influence.

By simply illuminating each stones, the board illuminates itself, revealing each players territory. It is then a battle of colors between two sides: the most intense influence is more likely to conquer the territory.


The beginners who just started to play have difficulties to see Atari. In order to help them, CGS will highlight this situation by reducing the size of stones that have only one liberty left.


To help new players to avoid being in Atari, CGS offer an option to show the liberty count of each stones.

Weak groups

Another complex concept for beginners to visualize is the strength or weakness that a group has on the board. Indirectly, the display of territories shows to what extent a group can be surrounded. With CGS, at a glance, a player will be able to spot if a group is endangered.

This way, it will be easier for a begginer to avoid placing a stone in dangerous areas.


In Go even players with different strength can play together in a balanced game thanks to handicap stones.

On CGS a ranking system attributes for each player a rank. Depending the difference of rank between two players and the board size the number of handicap stones will be automatically determined.

On a 19×19 board, we generally use one stone of handicap per rank difference. But on smaller board we should use a different ratio since a stone on a 9×9 board have well more impact than on a larger one.

On CGS we follow this handicap rule.
For example, if two players have 6 rank difference we use six handicap stones on a 19×19 board, three stones on 13×13 and only two on 9×9.


On CGS there is something for every taste! The player will be able to choose his preferred design among different themes while adjusting other parameters such as the intensity of the grid or the intensity of the influence.

User Interface

Game room

The game room show the list of current playing games and all challenges available.

The player can observe one of the current playing game by clicking on the corresponding row.

In the list of challenges, the player can accept one, by clicking on the “Play” button. He will see an information popup about the challenge with content such as clock or handicap. He can then confirm the challenge to start the game, or cancel it to find another one.

The player can create a new challenge by pressing the Play button.
The Play button will show the Automatch popup that allow him to automatically find an opponent that match the game’s criterias he selected.

Custom challenge

By default when the player clicks on the “Play” button. This will open the “Automatch” popup that show just a few choices. If the player wants to create a custom challenge, he can click on the settings icon of the “Automatch” popup.

Then a more complete popup will appear showing all the customizable options like game name, Komi, handicap, players color, clock system…

Board screen

The user interface is revisited in order to make it looks like a versus fighting video game. This will be more fun for casual players.

The interface is inspired by medieval fantasy to better harmonize with the style of the game board.
Even if the design is relooked, the interface features remain classical:

  • a board
  • a chat
  • a section for each player which contains: the display name, the avatar, the rank, the clock and the count of the captured stones
  • buttons to pass, resign or undo


When both players pass then the game enter in scoring mode. An automatic check is computed first in order to detect the dead stones. In most case the detector will select all dead stones. But in complex situations like Seki this maybe would not working as expected. This is why players have to verify dead stones and modify them if necessary.

Both players have to validate the dead stones in order the game end. Then a popup will appear to show the game’s outcome.


When you are playing or spectating a game you can see the spectator list. You can also invite a friend to join you.

Offline detection

In order to prevent abuse, CGS will automatically detect offline players. They will have 2 minutes to get back in the game otherwise they will lose the game.

You can create correspondence games that allow players to be offline.


One of the most important action to do in order to progress in Go is having your games reviewed by a player stronger than you. Because the reviewer can highlight your mistakes and propose you better moves.

CGS offer tools to review your games by yourself or by another player in real time.

Ask for review

On CGS, you can also request a game review by simply clicking a button. This will automatically request it in the global chat.

Highlight coordinates

While playing/spectating a game or a review, you can write coordinates in the chat. This will be highlighted on the board when your mouse is over the coordinates text.

Also, you can “Ctrl + Click” on the board to automatically write the corresponding coordinates in the chat.

Player’s Profile

The player can open and edit their profile to change the avatar, adding their favorite proverb or presenting their self.
They can also see their rank evolution in a graph and the history of their played games.

Custom profile

You can customize your presentation with layout (italic, bold, color, size, alignment…) or add links to some game of the server.

Country selection

In your profile you can also select your country. This will help other players to know what language you speak as well as help you make new friends in your country!


By playing on CGS you will unlock sometimes new badges. They prove you made specific actions to obtain them. Like having played 50 ranked games.

In your profile you will see all the badges you unlocked so far. Also you can highlight one of them. If so you and other players will see the badge next to your avatar.


Go is an amazing game to play with friends. CGS allows you to make friends and challenge them.

You can see easily when your friends are online in order to chat or play with them.


Go is also a game of exchange. Players like to talk with each other to comment their moves or to discuss about Go news.

On CGS players will have the possibility to send private messages, create group conversations or talk on the public chats.

Load SGF files

Sometime you play a game in tournament or on another Go server and you want to know what were your mistakes. Like how your opponent built this big Moyo. One option is to use a tool to analyze your game.

On CGS you can load a SGF file from your computer to look at the evolution of the influence along the game. Maybe you will find out how to prevent your next opponent to build such a big Moyo!


One of the main goals of CGS is to be accessible around the world. This is why multiple languages will be available at launch like English, Dutch, French, German, Russian, Spanish and Swedish

At first launch CGS detect your native language and use it by default if available. Of course you will be able to change it manually in the settings.

If you want to help translating CGS into a language that isn’t listed above, please send an email to


When you register on CGS, you’ll have the opportunity to answer a few questions to improve your gaming experience:

  • If you don’t know the rules you will be redirected to a tutorial.
  • You will be able to indicate your level of play, if you know it, in order to start playing directly against players of your strength.
  • If you are a beginner, you will be offered to ask for help from other players to teach you the basics of the game.

Also, once logged in, the automatch window will advise you the appropriate board size according to your level.

Theme selection

During registration you will be asked to choose your favorite theme from those available.

Also if during the previous questions CGS detects that you are a beginner it will offer you the option to display the liberties of the stones.


This is the CGS homepage, it’s a first draft and may be subject to change.

Ideas under consideration

Go variants

Go is so elegant and simple that it can be played with a lot of variants. You can find a non exhaustive list here.

On CGS we want to bring as much variants as we can. Of course, at first stage, only the classical Go rule will be available. But soon after the release, some variants will come depending of their complexity to develop.

Ordered by feasibility, here is the list of variants CGS will include.

One Color Go

This variant is simple but you will need to have a good memory! Both players use stones of the same color. Each move, you have to remember where your stones are on the board.

Fortunately with the influence visuals of CGS, you will have some clues to help your memory.

Adventure mode

To really start playing Go smoothly, the best still is to be taught by someone who knows his basics.

This is why CGS should integrate an adventure mode in which, for example, the player will take on the role of a perfect beginner willing to become a Go champion. Accompanied by a virtual teacher, the game rules will be interactively transmitted to him. Exercises and confrontations against virtual opponents will encourage him to progress.

Throughout his advancement in this mode, the player will discover new rules and tips to improve his game:

  • Direction of play
  • Big moves
  • Easiest Josekis
  • Basic Tsumegos
  • Shapes

The aim will be to lead a new player to a 15-20 kuy level. He can then continue the adventure by taking part in tournaments that integrate real players his level.

Sponsorship and schools

A sponsorship system can also be added. A beginner would become the student of a more experienced player on the server. He would determine the level he wants to reach and will be directed to the teacher(s) most likely to make him achieve his goal.

Virtual schools could emerge on the server and enable the training of a greater number of students.

Gameplay analysis

Getting a game review will be simple as clicking on a button thanks to an automatic request. This way, someone more experienced can comment on the reviewed game and advise the player(s) involved.

An Artificial Intelligence can also be used to analyze a game.


  • When will CGS be released?
    on January 23, 2021 6:00 PM CET (Paris). To be informed as soon as possible about the release, you can subscribe to the newsletter below.
  • How to play on CGS ?
    The CGS Go server will be accessible worldwide through your internet browser at
  • Will CGS be free ?
    Yes, that is the aim, although servers have a cost. CGS will rely on players donations. Possibly with ads if donations are not enough.
  • In which language will CGS be available ?
    First, English, Dutch, French, German, Russian, Spanish ,Swedish, Danish, Norwegian, Chinese, Afrikaans, Portugues.
    If you want to help translating CGS into a language that isn’t listed above, please send an email to


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