Ahh ok so green and blue look ok but red need a rethink?
No other way round, green and blue have bigger forward volts drops so you reach 20V with less LEDs than the red.
Awww man thought I had it!
Ok so the LEDs in my circuit:
Blue Vf = 3.1V:
So 3.1 x 5 = 15.5v
Green Vf = 3.07V:
So 3.07 x 5 = 15.35V
What am I missing?
What am I missing?
The fact that on that schematic you showed 10 LEDs in series not 5. This changes the maths. 
Oh I thought I had done the red as 10 in series and the blue and green as 2 x 5 series each, I will check!
Edit: I've check my circuit and the red led's have 10 in series and the blue and green have 2 x 5 led series in parallel each.
The green and the blues look ok, but the voltage drop across 10 red LEDs is too close to 20v for the series resistor to regulate the current well enough. Go for two chains of 5 red leds too.
Yes looking good.
Okey dokey, off to produce a few pcb's. Can't thank everyone enough for your patience and help.