1.Make a new image with a white background. Size doesn’t matter

2. Switch to the channels pallet: Windows>Show Channels. Make a new channel

3.Select a light gray color from the Swatches pallet. Now select the Paintbrush tool and then select a soft brush from the brushed pallet. Paint a wavy stroke on this channel.

Go to Filter>Pixelate>Color Halftone. Use the default setting. Click OK.

Switch back to the Layers Pallet. Click on the background layer. Now make a new layer. Go to Selection>Load Selection and select "Alpha 1" where is say Channel

Choose a color from the Swatches Pallet. Go to Edit>Fill and for contents choose foreground color and click OK. I use the gradient to get this effect. but you can use the soild color as I did at the bottom ( red)

Add more effects to the dots with Photoshop's Layer Effects: Layer>Effects.