The next thing screwing you up is that your stroke weight is set to 3, but you're only moving the players 1 pixel at a time. More info can be found in the reference here. To disable this, simply call noSmooth() at the beginning of your sketch. You can prove this by taking a screenshot of your sketch and then sampling your colors. But since you're using the exact color values, this is screwing you up. In most sketches, this is a good thing, since it makes things look better. This causes your colors to be just a little different than what you expect.

The biggest thing throwing you off is the fact that Processing enables anti-aliasing by default. This was a real head scratcher- good question. I have also left comments so you know why I've added each bit of code. I know it's long, but you should be able to just copy and paste this in a processing sketch and it will work. If (TestColorP2(P2_Pixel) = P2_Edge) //See if P2 has crashed If (TestColorP1(P1_Pixel) = P1_Edge) //See if P1 has crashed P1_Pixel = get(P1_XPos, P1_YPos) //Declare is as P1 position Int TestColorP2 (color P2Test) //Detect what color P2 is touchingД¬olor P1_Pixel //This is the color P1 is touching Int TestColorP1 (color P1Test) //Detect what color P1 is touching If ((key = 'W') || (key = 'w')) //Controls P2 movement If (Game_State = true) //if the game is not overД¬ollision_Detection() //Detect any crashes Stroke(0, 255, 0) //Draw the starting positions Line(1, height - 2, width - 1, height - 2) Line(width - 2, 1, width - 2, height - 1) StrokeWeight(3) //Draw the edge of the screen if I take that bit away, nothing else detects.Д«oolean Player1_Up = false //Determins what way P1 is goingД«oolean Player2_Up = false //Determins what way P2 is goingД«oolean Game_State = false //see if the game is over (false = over)ДЇinal int P1_Edge = 0 //P1 crashed into the edgeДЇinal int P1_P1 = 1 //P1 crashed into P1ДЇinal int P1_P2 = 2 //P1 crashed into P2ДЇinal int P2_Edge = 3 //P2 crashed into the edgeДЇinal int P2_P2 = 4 //P2 crashed into P2ДЇinal int P2_P1 = 5 //P2 crashed into P1 It instantly finishes as they are already on themselves. I mark that with a red border.Д«ut the only one that seem to be working is when they crash into themselves when the game starts. I have different variables such as 'P1_edge' which is when p1 hits the edge of the screen. I tried to make a color collision detection but its not working. I started by making p1 and p2 move and leave a trail behind them. I have to make a tron type game with collision detection.

Detecting collision java lwjgl