hey I'm kind of a newbie at processing, and I'm trying to modify the mousepressed function for a code I borrowed off openprocessing.org.

basically what I want to happen is when I press right mouse button, the color of the water changes hue or color within HSB color mode.

here is the code. I have highlighted where I have been playing around in red.

final int W = 200;
final int H = 200;

final int zoom = 3;

final int Speed = 13;

final float A = 8;

float[][][] u = new float[W][H][3];

void setup() {
  size(400, 400, P3D);


  for(int i=0; i<W; i++) {
    for(int j=0; j<H; j++) {
      for(int k=0; k<3; k++) {
        u[i][j][k] = 0;
      }
    }
  }

  colorMode(HSB, 255);
}

void draw() {
  background(0,0,0);
  noStroke();


  translate(width/2-W, height/2-H);
  scale(zoom*0.9);

  for(int i=0; i<W-1; i++) {
    for(int j=0; j<H-1; j++) {
      fill(160,200,map(u[i][j][0],-255,255,-55,200) + 55);

      beginShape();
      vertex(i,j, u[i][j][0]*0.1);
      vertex(i+1,j, u[i+1][j][0]*0.1);
      vertex(i+1,j+1, u[i+1][j+1][0]*0.1);
      vertex(i,j+1, u[i][j+1][0]*0.1);
      endShape();
    }
  }

  for(int i=0; i<Speed; i++) {
    calc();
  }
}

void calc() {
  float B = 1/A;

  for(int i=0; i<W; i++) {
    for(int j=0; j<H; j++) {
      if(i==W-1 || j==H-1) {
        u[i][j][0] = 0;
      }
      else if(i==0 || j==0) {
        u[i][j][0] = 0;
      }
      else {
        u[i][j][0] = B * ( -A*u[i][j][2] + 2*(A-2)*u[i][j][1] + u[i-1][j][1] + u[i+1][j][1] + u[i][j-1][1] + u[i][j+1][1]) * 0.99;
      }
    }
  }

  for(int i=0; i<W; i++) {
    for(int j=0; j<H; j++) {
      u[i][j][2] = u[i][j][1];
      u[i][j][1] = u[i][j][0];
    }
  }
}

void mousePressed() {
  u[constrain(mouseX/zoom,0,W-1)][constrain(mouseY/zoom,0,H-1)][2] = 255;
if (mousePressed = RIGHT){
  fill(random(0,255));
}
}
void mouseDragged() {
  u[constrain(mouseX/zoom,0,W-1)][constrain(mouseY/zoom,0,H-1)][2] = 100;
}