diff --git a/ATTRIBUTION.md b/ATTRIBUTION.md
index 3ccb702..f9b8c3d 100644
--- a/ATTRIBUTION.md
+++ b/ATTRIBUTION.md
@@ -1,5 +1,35 @@
 # Attribution
 
+## Code
+
+- [Color Conversion Shader](https://github.com/paddy-exe/ShaderFunction-Extras/blob/682301c10a4cc4dbe53b81dade46948e80e25c6a/addons/ShaderFunction-Extras/Color/LicenseInfo.md)
+
+```
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+```
+
 ## Fonts
 
-[Press Start Regular](https://www.1001fonts.com/press-start-font.html) by [codeman38](http://www.zone38.net/)
+- [Press Start Regular](https://www.1001fonts.com/press-start-font.html) by [codeman38](http://www.zone38.net/)
diff --git a/color/Colored.gd b/color/Colored.gd
new file mode 100644
index 0000000..9f90406
--- /dev/null
+++ b/color/Colored.gd
@@ -0,0 +1,14 @@
+extends Node
+class_name Colored
+
+@export var shader: Shader
+
+@onready var hue: float = Randomizer.rng.randf()
+@onready var parent: Sprite2D = get_parent()
+
+
+func _ready():
+	var material = ShaderMaterial.new()
+	material.shader = shader
+	material.set_shader_parameter("hue", hue)
+	parent.material = material
diff --git a/color/colored.tscn b/color/colored.tscn
new file mode 100644
index 0000000..fb95406
--- /dev/null
+++ b/color/colored.tscn
@@ -0,0 +1,6 @@
+[gd_scene load_steps=2 format=3 uid="uid://vkvtap437nnf"]
+
+[ext_resource type="Script" path="res://color/Colored.gd" id="1_wy58a"]
+
+[node name="Colored" type="Node"]
+script = ExtResource("1_wy58a")
diff --git a/entity/gem/gem.gd b/entity/gem/gem.gd
deleted file mode 100644
index ca10a58..0000000
--- a/entity/gem/gem.gd
+++ /dev/null
@@ -1,11 +0,0 @@
-extends RigidBody2D
-
-
-# Called when the node enters the scene tree for the first time.
-func _ready():
-	print($Valuable.value)
-
-
-# Called every frame. 'delta' is the elapsed time since the previous frame.
-func _process(delta):
-	pass
diff --git a/entity/gem/gem.tscn b/entity/gem/gem.tscn
index f5579d9..9bce7f2 100644
--- a/entity/gem/gem.tscn
+++ b/entity/gem/gem.tscn
@@ -1,9 +1,11 @@
-[gd_scene load_steps=8 format=3 uid="uid://w2er6cmul5yx"]
+[gd_scene load_steps=10 format=3 uid="uid://bawprh8kluilq"]
 
 [ext_resource type="PhysicsMaterial" uid="uid://c6kn1an85lccr" path="res://entity/coin_physics_material.tres" id="1_vmemd"]
 [ext_resource type="Texture2D" uid="uid://b21bsbo5f0ed7" path="res://entity/gem/gemstone.png" id="3_6jejy"]
+[ext_resource type="PackedScene" uid="uid://vkvtap437nnf" path="res://color/colored.tscn" id="4_2cetq"]
 [ext_resource type="PackedScene" uid="uid://bk1vvq5rug01m" path="res://collector/collectible.tscn" id="4_idoeu"]
 [ext_resource type="PackedScene" uid="uid://ujpra0s1kpqi" path="res://value/valuable.tscn" id="5_7bd6c"]
+[ext_resource type="Shader" path="res://entity/gem/gem_shading_material.gdshader" id="5_v6ppl"]
 [ext_resource type="Script" path="res://entity/gem/RandomValue.gd" id="6_3lulr"]
 [ext_resource type="AudioStream" uid="uid://br25ip30mu174" path="res://audio/conversione/mechanic_sound.wav" id="6_svrnw"]
 
@@ -29,6 +31,9 @@ shape = SubResource("CapsuleShape2D_jkfas")
 texture_filter = 1
 texture = ExtResource("3_6jejy")
 
+[node name="Colored" parent="CollisionShape2D/Sprite" instance=ExtResource("4_2cetq")]
+shader = ExtResource("5_v6ppl")
+
 [node name="Collectible" parent="." instance=ExtResource("4_idoeu")]
 type = &"Silver"
 
diff --git a/entity/gem/gem_shading_material.gdshader b/entity/gem/gem_shading_material.gdshader
new file mode 100644
index 0000000..7773a1a
--- /dev/null
+++ b/entity/gem/gem_shading_material.gdshader
@@ -0,0 +1,25 @@
+shader_type canvas_item;
+
+uniform float hue;
+
+vec3 hsv_to_rgb(vec3 color) {
+	vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
+	vec3 p = abs(fract(color.xxx + K.xyz) * 6.0 - K.www);
+	return color.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), color.y);
+}
+
+vec3 rgb_to_hsv(vec3 color) {
+	vec4 K = vec4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
+	vec4 p = mix(vec4(color.bg, K.wz), vec4(color.gb, K.xy), step(color.b, color.g));
+	vec4 q = mix(vec4(p.xyw, color.r), vec4(color.r, p.yzx), step(p.x, color.r));
+	float d = q.x - min(q.w, q.y);
+	float e = 1.0e-10;
+	return vec3(abs(q.z + (q.w - q.y) / (6.0 * d + e)), d / (q.x + e), q.x);
+}
+
+void fragment() {
+	vec3 hsv = rgb_to_hsv(COLOR.rgb);
+	hsv.x = hue;
+	vec3 rgb = hsv_to_rgb(hsv);
+	COLOR.rgb = rgb;
+}
diff --git a/entity/gem/gem_shading_material.tres b/entity/gem/gem_shading_material.tres
new file mode 100644
index 0000000..c660f00
--- /dev/null
+++ b/entity/gem/gem_shading_material.tres
@@ -0,0 +1,7 @@
+[gd_resource type="ShaderMaterial" load_steps=2 format=3 uid="uid://dbnxaw6yecsyv"]
+
+[ext_resource type="Shader" path="res://entity/gem/gem_shading_material.gdshader" id="1_h813y"]
+
+[resource]
+shader = ExtResource("1_h813y")
+shader_parameter/hue = 0.0
diff --git a/game/game.tscn b/game/game.tscn
index 2d8c926..05c4bbe 100644
--- a/game/game.tscn
+++ b/game/game.tscn
@@ -11,7 +11,7 @@
 [ext_resource type="PackedScene" uid="uid://du3005kwybbrh" path="res://entity/coin_gold/coin_gold.tscn" id="7_hh80i"]
 [ext_resource type="PackedScene" uid="uid://ratkps4plkhl" path="res://converters/copper_to_silver/copper_converter.tscn" id="7_ipeok"]
 [ext_resource type="PackedScene" uid="uid://but1bdslxp5jl" path="res://converters/silver_to_gold/silver_converter.tscn" id="8_0bbpi"]
-[ext_resource type="PackedScene" path="res://entity/gem/gem.tscn" id="8_a3sk0"]
+[ext_resource type="PackedScene" uid="uid://bawprh8kluilq" path="res://entity/gem/gem.tscn" id="8_a3sk0"]
 [ext_resource type="PackedScene" uid="uid://c2rlx7egl7xiv" path="res://collector/universal_collector.tscn" id="9_7op48"]
 [ext_resource type="PackedScene" uid="uid://c5w3b55aiui6c" path="res://collector/collector.tscn" id="9_evdhb"]
 [ext_resource type="Theme" uid="uid://ba5utvfhnxa5i" path="res://interface/interface_theme.tres" id="10_sayqn"]
@@ -61,7 +61,7 @@ shape = SubResource("RectangleShape2D_4uksi")
 debug_color = Color(0, 0.6, 0.701961, 0)
 
 [node name="Timer" type="Timer" parent="TimeSpawner"]
-wait_time = 0.02
+wait_time = 0.1
 autostart = true
 
 [node name="ButtonSpawner" parent="." node_paths=PackedStringArray("target") instance=ExtResource("3_qwsty")]