Mixed Colors LED project
4 strings in parallel, each string consisting of 4 LEDs (1 of each color) and a 100-ohm resistor in series - so you have 4 resistors (1 for each string).
The order you connect things in each series string doesn't matter. 

The sum of LED voltage drops in each string adds up to about 10V (assuming your stated specs are accurate), so this leaves 2V across the resistor.
Ohm's law tells us that for 20mA to flow through a resistor with 2V across it, the resistor must be 100 ohms.  

To be safe, you might want to increase the resistor value to 120 ohms - in case your LED voltage drops sum to less than 10V.







simulate this circuit &ndash; Schematic created using CircuitLab