How to correctly calculate power requirements for RGB led strip? Got totally confused working on some DIY custom furniture lighting.

This is my thinking process so please correct me if I'm wrong. For single color led strip (e.g. white) you just count how many leds you use and multiply that number with 20mA assuming each led is using 20mA of power. For RGB led is it like 3 leds in one (red, green and blue in one) or like one led power wise? Is one RGB led consuming 20mA or 3x20=60mA ?

 

It depends on how the strip is set up. The RGB LED strips I have have 3 RGB LEDs in a segment, each colour is in series with a 150,200 and 300 Ohm resistor depending on the colour, so each segment of colour will consume the 20mA.

In my case each LED segment of three consumes around 60mA.

If each individual RGB LED colour is wired in series with it's own resistor then it would be 60mA for each LED.