Help with drawing 30 circles going in a circle JOGL

OpenGL OpenGL: Basic Coding
1

I have managed to draw a single circle, but i can’t manage to craw 30 circles going in a circle.
They also need to change color for each circle drawn.
Can someone please help me with this?

Here is the code for the single circle.

 public void drawGLScene1(GLAutoDrawable glDrawable) {	
                GL gl = glDrawable.getGL();
		gl.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
		gl.glLoadIdentity();
		gl.glTranslatef(-10.0f, 0.0f, -20.0f);
		gl.glColor3f(0f, 0f, 1f);
		gl.glBegin(gl.GL_LINE_LOOP);
		for (int i = 0; i < 100; i++){
			double angle = 2*Math.PI*i/100;
			double x = Math.cos(angle);
			double y = Math.sin(angle);
			gl.glVertex3f((float)x,(float)y, (float)0.0);
		}
		gl.glEnd();
	}