If you're not familiar with adjustment layers, go to Adjustment Layers and Levels.
To create an adjustment layer, click the Create adjustment layer icon.
The Create adjustment layer icon is located at the bottom of the Layers panel.
The icon looks is a half black, half white, circle.
A menu will open.
Select the adjustment layer that you need.
The adjustment layer will:
• Appear in the layers stack.
• Open in the Adjustments panel.
The most used adjustment layers are Levels and Hue/Saturation.
Levels changes the exposure and contrast.
Hue/Saturation changes the color.
You can use the Photo Filter adjustment layer for color correction.
Go to Adjustment Layers.
You may need to go back to an adjustment layer to change its settings.
To reopen an adjustment layer, double click the icon in the adjustment layer.
After using an adjustment layer, compare the changed photograph to the unchanged photograph.
There are two methods.
Click the eye icon on the adjustment layer to hide the layer.
Click it again to make the layer visible again.
At the bottom of the Adjustments panel, click and hold the third icon to hide the layer momentarily.