The LEDs are transparent and mixed, so you have to test them one by one to know the color. I used a USB power supply and put a resistor in series with the LED test. A value between 150 Ohm and 1 KOhm appropriate.
All LEDs work. I have 19 blue, yellow 19, green 19, 20 red, 20 white. So I have 97 LED instead of 100, but that is enough.