Can a RadialGradientPaint have multiple center points?

Question

I am currently trying to add a day/night cycle to my game, and I am having trouble with lighting. If there is a light source, I want it to create a circle of light around its area. I've made night time by drawing a black rectangle over the screen that becomes less transparent when its night time. That makes the whole screen darker. The code that I have works for one light source, but if I have a light source that overlaps another light source, it makes a strange darker ring. I understand what is causing that ring, but nothing I have tried is removing the ring.

public void render(Graphics g) {
        Graphics2D g2d = (Graphics2D) g;
        g2d.setColor(new Color(20, 20, 20, transparency));

        float[] dist = { 0.5f, 1.0f };
        Color[] color = { new Color(230, 230, 180, 150), new Color(20, 20, 20, transparency) };
        //Color[] color = { new Color(230, 230, 180, 150), new Color(0, 0, 0, 0) }; //Old unused color for the gradient
        Area a = new Area(new Rectangle(0, 0, Main_Game.WIDTH, Main_Game.HEIGHT));
        for (int i = 0; i < lightList.size(); i++) {
            RadialGradientPaint p = new RadialGradientPaint(lightList.get(i).center, lightList.get(i).size, dist, color);
            g2d.setPaint(p);
            g2d.fillOval(lightList.get(i).center.x - lightList.get(i).size, lightList.get(i).center.y - lightList.get(i).size, lightList.get(i).size*2, lightList.get(i).size*2);
            a.subtract(new Area(new Ellipse2D.Double(lightList.get(i).center.x - lightList.get(i).size, lightList.get(i).center.y - lightList.get(i).size, lightList.get(i).size*2, lightList.get(i).size*2)));
        }
        g2d.setColor(new Color(20, 20, 20, transparency));
        g2d.fill(a);
    }

That code has a linked list that holds all the light sources. And the transparency variable stores the transparency the box that darkens the screen when it's night time.

The ideal way to fix this would be to combine all the RadialGradientPaint objects for each light into one paint object and that way, the lights wouldn't overlap weirdly.

Here is what it looks like when it works with only one light source:

Here is a picture of the weirdness of lighting that I'm getting at night time (there is no issue during the daytime of the game) when there are two light sources close to each other:

Any sort of help or recommendation to setup this lighting would be greatly appreciated :)

I have tried subtracting one lighting circle from another so that they aren't overlapping, but that made the two lights not merge very nicely. I tried drawing the lights as a rectangle instead of an oval but that made a similar issue.