Why my 12V RGB LED strip controlled by Arduino Uno has reversed colors and when I set RGB to 0,0,0 (after reverse) strip should be black but its red?

Question

This is scheme:

Transistors: BD912, PNP, 15A, 100V, 90W, TO220.

And this is color of "black":

and this is code:

const int redPin = 5;
const int greenPin = 6;
const int bluePin = 3;

void setup() {
  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(bluePin, OUTPUT);
}

void loop() {

  analogWrite(redPin, 255);
  analogWrite(greenPin, 255);
  analogWrite(bluePin, 255);

}
```

Answer 1

Looks like you have a pictorial diagram that is intended to use N-channel MOSFETs and you've subsituted BD912 PNP transistors (without base resistors).

If accurate, that's not going to work and you may have damaged the Arduino.

Answer 2

const int redPin = 5;     // Red is wired to pin 6.
const int greenPin = 6;   // Green is wired to pin 9.
const int bluePin = 3;    // Blue wired to pin 5.