The forward voltage of your LEDs is very low (1.5V to 1.6V) so I think they are infrared ones. Then you won't see them. They might burn your eyes.
Red is about 1.8V to 2.0V, yellow and old green is 2.2V and new green, blue and white is about 3.5V to 4.5V.
Red is about 1.8V to 2.0V, yellow and old green is 2.2V and new green, blue and white is about 3.5V to 4.5V.
