Added tip about gamma in Color Correction section (#742)

components/light/rgb.rst

@@ -60,6 +60,9 @@ perceived intensity of different colors will generally vary. This can be done by
         max_power: 80%
       # Repeat for green and blue output
 
+.. note::
+
+    Remember that ``gamma_correct`` is enabled by default (``γ=2.8``), and you may want take it into account for the calibration. For instance if you command a light to *50%* brightness and want it to be the new maximum: ``max_PWM_power = max_light_power^2.8 = 0.5^2.8 = 0.144``, then you would set ``max_power`` to *14.4%*.
 
 Configuration variables:
 ------------------------

components/light/rgbw.rst

@@ -43,6 +43,10 @@ perceived intensity of different colors will generally vary. This can be done by
         pin: D1
         max_power: 80%
 
+.. note::
+
+    Remember that ``gamma_correct`` is enabled by default (``γ=2.8``), and you may want take it into account for the calibration. For instance if you command a light to *50%* brightness and want it to be the new maximum: ``max_PWM_power = max_light_power^2.8 = 0.5^2.8 = 0.144``, then you would set ``max_power`` to *14.4%*.
+
 .. _rgbw_color_interlock:
 
 Color Interlock

components/light/rgbww.rst

@@ -49,6 +49,10 @@ perceived intensity of different colors will generally vary. This can be done by
         pin: D1
         max_power: 80%
 
+.. note::
+
+    Remember that ``gamma_correct`` is enabled by default (``γ=2.8``), and you may want take it into account for the calibration. For instance if you command a light to *50%* brightness and want it to be the new maximum: ``max_PWM_power = max_light_power^2.8 = 0.5^2.8 = 0.144``, then you would set ``max_power`` to *14.4%*.
+
 Color Interlock
 ---------------