How do I change the color to transparent in Photopea?

You can adjust the layer's opacity to make a color transparent in Photopea. By reducing the opacity to 0%, the layer becomes completely transparent.

Here's how you do it:

1. Select the layer you want to make transparent in the Layers panel.
2. Locate the Opacity slider at the top of the Layers panel.
3. Adjust the slider: Drag the slider down. At 0%, the layer will be completely transparent (invisible), and at 100%, it will have no transparency. A setting around 50% will make the color partially transparent.