diff --git a/backend/models/models.go b/backend/models/models.go
index 5fe5f85..3172d23 100644
--- a/backend/models/models.go
+++ b/backend/models/models.go
@@ -1,71 +1,75 @@
-package models
-
-import "time"
-
-type User struct {
-	Name    string `json:"name"`
-	IsAdmin bool   `json:"is_admin"`
-}
-
-type MIME struct {
-	Name      string `json:"name"`
-	Extension string `json:"extension"`
-}
-
-type Category struct {
-	ID        string    `json:"id"`
-	Name      string    `json:"name"`
-	Color     string    `json:"color"`
-	CreatedAt time.Time `json:"created_at"`
-	Creator   User      `json:"creator"`
-}
-
-type File struct {
-	ID        string    `json:"id"`
-	Name      string    `json:"name"`
-	MIME      MIME      `json:"mime"`
-	CreatedAt time.Time `json:"created_at"`
-	Creator   User      `json:"creator"`
-}
-
-type Tag struct {
-	ID        string    `json:"id"`
-	Name      string    `json:"name"`
-	Color     string    `json:"color"`
-	Category  Category  `json:"category"`
-	CreatedAt time.Time `json:"created_at"`
-	Creator   User      `json:"creator"`
-}
-
-type Autotag struct {
-	TriggerTag Tag  `json:"trigger_tag"`
-	AddTag     Tag  `json:"add_tag"`
-	IsActive   bool `json:"is_active"`
-}
-
-type Pool struct {
-	ID        string    `json:"id"`
-	Name      string    `json:"name"`
-	CreatedAt time.Time `json:"created_at"`
-	Creator   User      `json:"creator"`
-}
-
-type Session struct {
-	ID           int       `json:"id"`
-	UserAgent    string    `json:"user_agent"`
-	StartedAt    time.Time `json:"started_at"`
-	ExpiresAt    time.Time `json:"expires_at"`
-	LastActivity time.Time `json:"last_activity"`
-}
-
-type Pagination struct {
-	Total  int `json:"total"`
-	Offset int `json:"offset"`
-	Limit  int `json:"limit"`
-	Count  int `json:"count"`
-}
-
-type Slice[T any] struct {
-	Pagination Pagination `json:"pagination"`
-	Data       []T        `json:"data"`
-}
+package models
+
+import (
+	"time"
+
+	"github.com/jackc/pgx/v5/pgtype"
+)
+
+type User struct {
+	Name    string `json:"name"`
+	IsAdmin bool   `json:"is_admin"`
+}
+
+type MIME struct {
+	Name      string `json:"name"`
+	Extension string `json:"extension"`
+}
+
+type Category struct {
+	ID        string      `json:"id"`
+	Name      string      `json:"name"`
+	Color     pgtype.Text `json:"color"`
+	CreatedAt time.Time   `json:"created_at"`
+	Creator   User        `json:"creator"`
+}
+
+type File struct {
+	ID        string      `json:"id"`
+	Name      pgtype.Text `json:"name"`
+	MIME      MIME        `json:"mime"`
+	CreatedAt time.Time   `json:"created_at"`
+	Creator   User        `json:"creator"`
+}
+
+type Tag struct {
+	ID        string      `json:"id"`
+	Name      string      `json:"name"`
+	Color     pgtype.Text `json:"color"`
+	Category  Category    `json:"category"`
+	CreatedAt time.Time   `json:"created_at"`
+	Creator   User        `json:"creator"`
+}
+
+type Autotag struct {
+	TriggerTag Tag  `json:"trigger_tag"`
+	AddTag     Tag  `json:"add_tag"`
+	IsActive   bool `json:"is_active"`
+}
+
+type Pool struct {
+	ID        string    `json:"id"`
+	Name      string    `json:"name"`
+	CreatedAt time.Time `json:"created_at"`
+	Creator   User      `json:"creator"`
+}
+
+type Session struct {
+	ID           int       `json:"id"`
+	UserAgent    string    `json:"user_agent"`
+	StartedAt    time.Time `json:"started_at"`
+	ExpiresAt    time.Time `json:"expires_at"`
+	LastActivity time.Time `json:"last_activity"`
+}
+
+type Pagination struct {
+	Total  int `json:"total"`
+	Offset int `json:"offset"`
+	Limit  int `json:"limit"`
+	Count  int `json:"count"`
+}
+
+type Slice[T any] struct {
+	Pagination Pagination `json:"pagination"`
+	Data       []T        `json:"data"`
+}