I’ve seen people apply color to areas of an image by creating a new layer set to the Color blending mode and painting on that layer with the Brush tool (B). This is an extremely bad way to do it. Creating a layer and filling it with the Foreground or Background color is better, but still not the best way. 

Instead, use a Solid Color or Gradient fill layer to create color overlays. Click the Create New Fill Layer icon (half-black/half-white circle) at the bottom of the Layers panel and choose Solid Color or Gradient. Select the colors you want to use, and click OK. You can change the blending modes to get the effects you’re looking for and then mask out the adjustment wherever you don’t want it. To top things off, using a fill layer keeps your document size smaller than a layer filled with pixels

This tip originally published in Colin Smith’s “Photoshop Tips” column in the March, 2023 issue oPhotoshop User magazine.