Step 1: Open up “GIMP 2.10″, right-click anywhere on the screen and open the image that you have chosen to color change.
Step 2: Right-click anywhere on the screen again, hover over the “Colors >” Tab and press “Curves…”
you will then be greeted with another window like this one below.
You can adjust any way you would like, go up or down, left or right, “wibble wobble” that line to find the brightness that is perfect for you.
To change the colors, right-click and hover over “Colors >” and select “Hue-Saturation…”
This time, you will be greeted with this window:
(OPTIONAL) Step 3: You can layer mask the image as well to separate a part of the picture and color it without affecting the other images.
Select the image and right click on the layer and select “Apply Layer Mask…”
I recommend duplicating the image just in case something goes wrong with the picture.
Upon selecting “Apply Layer Mask…” you will be greeted with another windows like this.
You have to use “White (Full Opacity)” you can choose to invert the mask or not, it depends on you. Once you are sure that your settings are correct, proceed by pressing “Add” and start using the brush to separate the area, if you have the “Invert Mask” selected, you have to use an eraser this time.
Layer Mask I did on the picture (The Sky):
And there you have it, you have finished your “Color Changing” assignment.
My image before and after:
A “Walkthrough” of how I changed the colors for images.