diff --git a/src/Bundle/ChillMainBundle/Entity/UserGroup.php b/src/Bundle/ChillMainBundle/Entity/UserGroup.php
index d6e343d00..470a21a70 100644
--- a/src/Bundle/ChillMainBundle/Entity/UserGroup.php
+++ b/src/Bundle/ChillMainBundle/Entity/UserGroup.php
@@ -38,6 +38,24 @@ class UserGroup
     #[ORM\JoinTable(name: 'chill_main_user_group_user')]
     private Collection $users;
 
+    #[ORM\Column(type: 'text', nullable: false, options: ['default' => '#ffffffff'])]
+    #[Serializer\Groups(['read'])]
+    private string $backgroundColor = '#ffffffff';
+
+    #[ORM\Column(type: 'text', nullable: false, options: ['default' => '#000000ff'])]
+    #[Serializer\Groups(['read'])]
+    private string $foregroundColor = '#000000ff';
+
+    /**
+     * Groups with same exclude key are mutually exclusive: adding one in a many-to-one relationship
+     * will exclude others.
+     *
+     * An empty string means "no exclusion"
+     */
+    #[ORM\Column(type: 'text', nullable: false, options: ['default' => ''])]
+    #[Serializer\Groups(['read'])]
+    private string $excludeKey = '';
+
     public function __construct()
     {
         $this->users = new ArrayCollection();
@@ -75,4 +93,47 @@ class UserGroup
     {
         return $this->users;
     }
+
+    public function getForegroundColor(): string
+    {
+        return $this->foregroundColor;
+    }
+
+    public function getExcludeKey(): string
+    {
+        return $this->excludeKey;
+    }
+
+    public function getBackgroundColor(): string
+    {
+        return $this->backgroundColor;
+    }
+
+    public function setForegroundColor(string $foregroundColor): self
+    {
+        $this->foregroundColor = $foregroundColor;
+
+        return $this;
+    }
+
+    public function setBackgroundColor(string $backgroundColor): self
+    {
+        $this->backgroundColor = $backgroundColor;
+
+        return $this;
+    }
+
+    public function setExcludeKey(string $excludeKey): self
+    {
+        $this->excludeKey = $excludeKey;
+
+        return $this;
+    }
+
+    public function setLabel(array $label): self
+    {
+        $this->label = $label;
+
+        return $this;
+    }
 }
diff --git a/src/Bundle/ChillMainBundle/Resources/public/types.ts b/src/Bundle/ChillMainBundle/Resources/public/types.ts
index 2e33b8248..840a0e939 100644
--- a/src/Bundle/ChillMainBundle/Resources/public/types.ts
+++ b/src/Bundle/ChillMainBundle/Resources/public/types.ts
@@ -42,6 +42,15 @@ export interface User {
   // todo: mainCenter; mainJob; etc..
 }
 
+export interface UserGroup {
+    type: "chill_main_user_group",
+    id: number,
+    label: TranslatableString,
+    backgroundColor: string,
+    foregroundColor: string,
+    excludeKey: string,
+}
+
 export interface UserAssociatedInterface {
   type: "user";
   id: number;
diff --git a/src/Bundle/ChillMainBundle/migrations/Version20240422091752.php b/src/Bundle/ChillMainBundle/migrations/Version20240422091752.php
new file mode 100644
index 000000000..960b3cc79
--- /dev/null
+++ b/src/Bundle/ChillMainBundle/migrations/Version20240422091752.php
@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * Chill is a software for social workers
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Chill\Migrations\Main;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+final class Version20240422091752 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'Add colors and exclude string to user groups';
+    }
+
+    public function up(Schema $schema): void
+    {
+        $this->addSql('ALTER TABLE chill_main_user_group ADD backgroundColor TEXT DEFAULT \'#ffffffff\' NOT NULL');
+        $this->addSql('ALTER TABLE chill_main_user_group ADD foregroundColor TEXT DEFAULT \'#000000ff\' NOT NULL');
+        $this->addSql('ALTER TABLE chill_main_user_group ADD excludeKey TEXT DEFAULT \'\' NOT NULL');
+        $this->addSql('ALTER INDEX idx_1e07f044d2112630 RENAME TO IDX_738BC82BD2112630');
+        $this->addSql('ALTER INDEX idx_1e07f044a76ed395 RENAME TO IDX_738BC82BA76ED395');
+    }
+
+    public function down(Schema $schema): void
+    {
+        $this->addSql('ALTER TABLE chill_main_user_group DROP backgroundColor');
+        $this->addSql('ALTER TABLE chill_main_user_group DROP foregroundColor');
+        $this->addSql('ALTER TABLE chill_main_user_group DROP excludeKey');
+        $this->addSql('ALTER INDEX idx_738bc82bd2112630 RENAME TO idx_1e07f044d2112630');
+        $this->addSql('ALTER INDEX idx_738bc82ba76ed395 RENAME TO idx_1e07f044a76ed395');
+    }
+}