So first things first: a lot of the eyes in Brawl are extremely boring and simple but if you want to spice up the coloring for your hacks then read on.
This tutorial will use vBrawl Zelda's Eye as a base.
Step 1 - *Optional* - Contrast:
Open your eye texture in gimp and use the brightness/contrast tool in the colors tab to make the variation between dark and light bigger therefore more dramatic and appealing. I used 30 on both.
Step 2 - Color:
Choose between the Hue-Saturation and colorize tools in the colors tab to change the color of the eye to whatever color you want it to be. I used the Hue-Saturation tool and adjusted the hue to 180 to make it brown. Feel free to reuse step 1 and 2 throughout the rest for all of the layers you'll add!
Step 3 - Lower Aurora effect
Decide on a color you want to highlight the underside of the pupil, I've chosen teal although a color closer to the original could be better such as orange in this case, then create a new layer, set your brush size to something small, in my case I'm using 3, then use the pixel brush with the airbrush tool, I'm using the airbrush with it's default start-up settings, and brush up the area around the pupil that is being affected by light. Once you've colored that area with the airbrush select the smudge tool, change your brush to one of Gimp's default brushes called Bristle 02 or any brush that is light random noise and start smudging the color of the new layer until the change between the main color and the new color isn't so extreme; a tip is to smudge from the center of the pupil outward and if needed change the layer's opacity to something below 100, I've set mine to 96.
Step 4 - U Aurora effect
Extremely similar to step 3 except choose a different color, I've chosen yellow, and make the higlights closer and all around the pupil and smuding the darker areas more than the lighter ones. I suggest you don't merge down the layers until the end.
Step 5 - Sun Aurora effect
Like step 3 and four choose a color, I've chosen lime green, and this time your highlights will go from the pupil all the way to the edge of the cornea but as rays instead, which is why it's dubbed the sun effect. For this one use a more solid brush like one of the hardness ones to smudge the darker areas while still using the same as the previous steps for the lighter areas. After you've smudged it a bit lower the opacity of the layer to whatever you think looks best then you can clean up the layers if needed and merge them down!
This process can have great results although the one created for this tutorial isn't really that good. Either way here's the finished PNG for the example:
Edit!: Can't believe I just remembered, if you want the eye to truly be higher quality you can modify that when importing the image with brawlbox! Use CI8 with the highest quality possible! It'll take some extra data but its still an option! xD
