diff --git a/src/ColorModels/AbstractColorModel.php b/src/ColorModels/AbstractColorModel.php
new file mode 100644
index 0000000..5db61f3
--- /dev/null
+++ b/src/ColorModels/AbstractColorModel.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace TorstenHettstedt\Colors\ColorModels;
+
+
+use InvalidArgumentException;
+
+abstract class AbstractColorModel
+{
+
+    protected function checkValue(float $value)
+    {
+        if ($value > 1.0) {
+            throw new InvalidArgumentException('Ein Wert größer als 1 ist nicht definierbar.');
+        }
+        if ($value < 0.0) {
+            throw new InvalidArgumentException('Ein Wert kleiner als 0 ist nicht definierbar.');
+        }
+    }
+
+}
\ No newline at end of file
diff --git a/src/ColorModels/RedGreenBlue.php b/src/ColorModels/RedGreenBlue.php
new file mode 100644
index 0000000..f38e7e1
--- /dev/null
+++ b/src/ColorModels/RedGreenBlue.php
@@ -0,0 +1,75 @@
+<?php
+
+namespace TorstenHettstedt\Colors\ColorModels;
+
+/**
+ * Definition des allgemeinen RGB-Farbraumes. Die Werte für die eigenschaften sind reelle Zahlen von 0 bis einschließlich 1.
+ * Ohne Änderung der Eigenschaften wird die Farbe *weiß* dargestellt.
+ */
+class RedGreenBlue extends AbstractColorModel
+{
+    /** @var float : Definition des Rotanteil */
+    protected float $red = 1.0;
+    /** @var float : Definition des Grünanteil */
+    protected float $green = 1.0;
+    /** @var float : Definition des Grünanteil */
+    protected float $blue = 1.0;
+
+    /**
+     * @return float
+     */
+    public function getRed(): float
+    {
+        return $this->red;
+    }
+
+    /**
+     * @param float $red
+     * @return RedGreenBlue
+     */
+    public function setRed(float $red): RedGreenBlue
+    {
+        $this->checkValue($red);
+        $this->red = $red;
+        return $this;
+    }
+
+    /**
+     * @return float
+     */
+    public function getGreen(): float
+    {
+        return $this->green;
+    }
+
+    /**
+     * @param float $green
+     * @return RedGreenBlue
+     */
+    public function setGreen(float $green): RedGreenBlue
+    {
+        $this->checkValue($green);
+        $this->green = $green;
+        return $this;
+    }
+
+    /**
+     * @return float
+     */
+    public function getBlue(): float
+    {
+        return $this->blue;
+    }
+
+    /**
+     * @param float $blue
+     * @return RedGreenBlue
+     */
+    public function setBlue(float $blue): RedGreenBlue
+    {
+        $this->checkValue($blue);
+        $this->blue = $blue;
+        return $this;
+    }
+
+}
\ No newline at end of file
diff --git a/tests/unit/ColorModels/RedGreenBlueTest.php b/tests/unit/ColorModels/RedGreenBlueTest.php
new file mode 100644
index 0000000..b06e964
--- /dev/null
+++ b/tests/unit/ColorModels/RedGreenBlueTest.php
@@ -0,0 +1,120 @@
+<?php /** @noinspection PhpArrayShapeAttributeCanBeAddedInspection */
+
+namespace TorstenHettstedtUnitTests\Colors\ColorModels;
+
+use Codeception\Test\Unit;
+use InvalidArgumentException;
+use TorstenHettstedt\Colors\ColorModels\RedGreenBlue;
+
+class RedGreenBlueTest extends Unit
+{
+
+    public function testConstruct()
+    {
+        $color = new RedGreenBlue();
+
+        $this->assertEquals(1.0, $color->getRed());
+        $this->assertEquals(1.0, $color->getGreen());
+        $this->assertEquals(1.0, $color->getBlue());
+    }
+
+    /**
+     * @return float[][]
+     */
+    public function invalidValueProvider(): array
+    {
+        return [
+            'zu klein' => [-0.1],
+            'zu gross' => [1.1],
+        ];
+    }
+
+    /**
+     * @return float[][]
+     */
+    public function validValueProvider(): array
+    {
+        return [
+            'niedrigster Wert' => [0.0],
+            'mittlerer Wert' => [0.45],
+            'maximaler Wert' => [1.0],
+        ];
+    }
+
+    /**
+     * @param float $value
+     *
+     * @dataProvider validValueProvider
+     */
+    public function testSetRedWithValidValue(float $value)
+    {
+        $color = new RedGreenBlue();
+
+        $color->setRed($value);
+        $this->assertEquals($value, $color->getRed());
+    }
+
+    /**
+     * @param float $value
+     *
+     * @dataProvider invalidValueProvider
+     */
+    public function testSetRedWithInvalidValue(float $value)
+    {
+        $color = new RedGreenBlue();
+
+        $this->expectException(InvalidArgumentException::class);
+        $color->setRed($value);
+    }
+    /**
+     * @param float $value
+     *
+     * @dataProvider validValueProvider
+     */
+    public function testSetGreenWithValidValue(float $value)
+    {
+        $color = new RedGreenBlue();
+
+        $color->setGreen($value);
+        $this->assertEquals($value, $color->getGreen());
+    }
+
+    /**
+     * @param float $value
+     *
+     * @dataProvider invalidValueProvider
+     */
+    public function testSetGreenWithInvalidValue(float $value)
+    {
+        $color = new RedGreenBlue();
+
+        $this->expectException(InvalidArgumentException::class);
+        $color->setGreen($value);
+    }
+
+    /**
+     * @param float $value
+     *
+     * @dataProvider validValueProvider
+     */
+    public function testSetBlueWithValidValue(float $value)
+    {
+        $color = new RedGreenBlue();
+
+        $color->setBlue($value);
+        $this->assertEquals($value, $color->getBlue());
+    }
+
+    /**
+     * @param float $value
+     *
+     * @dataProvider invalidValueProvider
+     */
+    public function testSetBlueWithInvalidValue(float $value)
+    {
+        $color = new RedGreenBlue();
+
+        $this->expectException(InvalidArgumentException::class);
+        $color->setBlue($value);
+    }
+}