Apply changes to specific colours in a photo in Photos on Mac
You can adjust specific colours in a photo using the Selective Colour adjustment. For example, in a photo of a dog wearing a coloured hat, you might use the Selective Colour adjustment to change the colour of the dog’s hat.
You can select and change the hue, saturation, and luminance of up to six different colours in a photo.
In the Photos app on your Mac, double-click a photo, then click Edit in the toolbar.
Click Adjust in the toolbar.
In the Adjust pane, click the disclosure triangle next to Selective Colour.
Click a colour well to select it to store your colour change, click the Eyedropper button , then click a colour in the photo that you want to change.
With a colour selected, drag the sliders to change the colour:
Hue: Adjusts the hue of the selected colour. For example, you might change a green hue to blue.
Saturation: Increases or decreases the intensity of the selected colour. For example, by desaturating a vivid pink, you might change it to a light or nearly grey pink.
Luminance: Adjusts the luminance (the appearance of brightness or the amount of light reflected from a surface) of the selected colour.
Range: Adjusts the range of colours that change based on your colour selection. By changing the range you can increase or decrease how much similar colours are affected in the photo. For example, by increasing the range of a selected blue you might change all the blues shown in a sky or by decreasing the range, limit the change to a specific blue object.