A bi-colour LED has two different colour wired LEDs back to back in the same case, when the current flows in one direction, it's red and when it flows in the other direction it's green.
Tri-colour LEDs have two different LEDs in the same package, except their cathodes of anodes are alled wired to one pin and there are two other pins for each LED's annode or kathode. You can get three different colours by turning the LEDs on and off to mix different colours.
The angle, is the viewing angle.