Why is the color of LED display different?

1、 This is to change the current flowing through the LED. Generally, the LED tube allows a continuous working current of about 20 mA. Except that the red LED is saturated, the brightness of other LEDs is basically proportional to the current flowing;

2、 Using the visual inertia of the human eye, the pulse width modulation method is used to realize the gray level control, that is, the light pulse width (i.e. duty cycle) is changed periodically. As long as the cycle of repeated lighting is short enough (i.e. the refresh frequency is high enough), the human eye can not feel the shaking of luminous pixels. Because pulse width modulation is more suitable for digital control, almost all LED electronic displays use pulse width modulation to control gray level when microcomputer is widely used to provide and display the content of LED display screen.