ProgressBar backgroung is black using libgdx - libgdx

Question

I have a question regarding background color for progress bar using Libgdx.
Why background color is black even if I set as RED or BLUE?
Here is my code:
public class HealthBar extends Actor {
private final float min = 0;
private float stepSize = 1;
private ProgressBar healthBar;
private ProgressBar.ProgressBarStyle barStyle;
private ProgressBar healthBarr;
public HealthBar(float width, float health) {
healthBar = new ProgressBar(min, health, stepSize,false , setSkin());
healthBar.setSize(width, 10);
healthBar.setPosition(getX(), getY());
healthBar.setAnimateDuration(.3f);
healthBar.setValue(1);
healthBar.setColor(Color.BLUE);
}
private ProgressBar.ProgressBarStyle setSkin() {
Color bgColor = new Color(100/256f, 100/256f,100/256f,100/256f);
Skin skin;
skin = new Skin();
Pixmap pixmap = new Pixmap(1, 10, Pixmap.Format.RGBA8888);
pixmap.fill();
skin.add("white", new Texture(pixmap));
ProgressBar.ProgressBarStyle barStyle;
barStyle = new ProgressBar.ProgressBarStyle(skin.newDrawable("white", bgColor), skin.newDrawable("white", Color.RED));
barStyle.knobAfter= barStyle.knob;
return barStyle;
}
#Override
public void draw(Batch batch, float parentAlpha) {
super.draw(batch, parentAlpha);
healthBar.draw(batch, parentAlpha);
> //I think that the problem is with this draw method
}
}
When I add this progress bar as child directly to the stage is draw fine with knob color as it's specified, maybe the problem is with progress style ...Can someone help me?

Answer 1

You give the progress bar a transparent color, so on different background it appears to have a different color. I guess your stage background is black, which nullifies this effect.
Color bgColor = new Color(
100 / 256f, // RED component
100 / 256f, // GREEN component
100 / 256f, // BLUE component
100 / 256f); // ALPHA component
To fix your problem set the alpha component to 1f, which means no transparency (fully opaque).
Color bgColor = new Color(
100 / 256f, // RED component
100 / 256f, // GREEN component
100 / 256f, // BLUE component
1f); // ALPHA component

Answer 2

I used some of the code above to figure out how to create a progress bar in libgdx, but I got the same problem as the author of this question.
Color bgColor = new Color(100/256f, 100/256f,100/256f,100/256f);
Skin skin;
skin = new Skin();
Pixmap pixmap = new Pixmap(1, 10, Pixmap.Format.RGBA8888);
pixmap.setColor(bgColor); // set the color
pixmap.fill();
You need to set the color when creating pixmap, otherwise it'll use the defaults. And by default you get a "transparent color".
From the Pixmap source:
public Pixmap (int width, int height, Format format) {
pixmap = new Gdx2DPixmap(width, height,
Format.toGdx2DPixmapFormat(format));
setColor(0, 0, 0, 0);
fill();
}
This constructor by default sets a black with alpha set to 0 - fully transparent.