This is a special lamp that helps you sleep well. I use the RGB LED to make this lamp, it's elegant if you add a cover.

Supplies

1x Arduino Leonardo

5x Wires

4x Clip wires

1x RGB LED

1x Paper

1x 100ohm resistor

Step 1: Code

The link for full codes: Arduino CC

//RGB LED lamp
//The color of LED changes in the order of red, orange, yellow, green, blue, dark blue, and then purple.
//The RGB LED is controlled by the color of red, green, and blue
//Pin 7 controls the brightness of the red
//Pin 6 controls the brightness of the green
//Pin 5 controls the brightness of the blue 
void setup(){  // put your setup code here, to run once:
}
void loop(){  // Main code
  analogWrite(7 , 255);  //改
  analogWrite(6 , 0);  //改
  analogWrite(5 , 0);  //改
  delay( 1000 ); // waits a few milliseconds
  //Red
  analogWrite(7 , 255);  //改
  analogWrite(6 , 120);  //改
  analogWrite(5 , 0);  //改
  delay( 1000 ); // waits a few milliseconds
  //Orange
  analogWrite(7 , 255);//改
  analogWrite(6 , 255);  //改
  analogWrite(5 , 0);  //改
  delay( 1000 ); // waits a few milliseconds
  //Yellow
  analogWrite(7 , 0);  //改
  analogWrite(6 , 255);  //改
  analogWrite(5 , 0);  //改
  delay( 1000 ); // waits a few milliseconds
  //Green
  analogWrite(7 , 0);  //改
  analogWrite(6 , 255);  //改
  analogWrite(5 , 255);  //改
  delay( 1000 ); // waits a few milliseconds
  //Blue
  analogWrite(7 , 0);  //改
  analogWrite(6 , 0);  //改
  analogWrite(5 , 255);  //改
  delay( 1000 ); // waits a few milliseconds
  //Dark Blue
  analogWrite(7 , 130);  //改
  analogWrite(6 , 0);  //改
  analogWrite(5 , 255);  //改
  delay( 1000 ); // waits a few milliseconds
  //Purple
}

Step 2: Explain

RGB LED is controlled by a negative polarity and three kinds of light: Red, Green, and Blue. These three colors are the primary colors of light. Different brightness for each color combined can make almost all kinds of color. I choose the colors of the rainbow: red, orange, yellow, green, blue, dark blue, and violet to be the colors of my lamp.