I'm trying to generate a random color transition with a few restrictions.

I want to change each HSB value like I can change the RGB values in Photoshop with a curve like this:

Of course processing needs the mathematical function to describe this gradient. (my first problem)

My second problem is generating random curves with a restriction that the curve never drops like this:


Here is what I got so far:

1. void setup(){
     size (300,300);
   }
   
    
   void draw() {
   
   colorMode(HSB);
   float h = 1.;
   float s = 1;
   float b = 1;
   for (float i = 0; i < 300; i++) {
    
      
       stroke(h, s, b);
       line(i, 0, i, 300);
       h += 0.5;
       s += 0.3;
       b +=0.8;
   }
   
   }
   

I'm a beginner, so bare with me.

Rheinhard