controlP5 shading

Hi, I'm new to controlP5 and am trying to figure out why my slider is only adjusting greyscale and not the color I have inputted. I assume I will have to use the color sliders for this implementation? Thanks

import controlP5.*;

ControlP5 cp5;

int sliderValue2 = 100;
color sliderValue = color(255, 0, 255);
Slider abc;

void setup() {
  size(700, 400);
  noStroke();
  cp5 = new ControlP5(this);

  cp5.addSlider("sliderValue2")
    .setPosition(width/2 - 100, 50)
    .setSize(200, 20)
    .setRange(0, 255)
    .setNumberOfTickMarks(5)
    .setSliderMode(Slider.FLEXIBLE)
    ;

  cp5.addSlider("sliderValue")
    .setPosition(width/2 - 100, 150)
    .setSize(200, 20)
    .setRange(0, 255)
    .setNumberOfTickMarks(5)
    .setSliderMode(Slider.FLEXIBLE)
    ;
}

void draw() {
  background(sliderValue);

  fill(sliderValue2);
  rect(0, 0, width, 100);

}