right click on the model in the animation set editor under the skin option are the skin colors to change hair color right click on the model in the animation set editor then add override materials then right click again go on show in element viewer then click on model then go to materials and change teamcolor

for the agent 8 hair (assuming you already have it downloaded), right click and go to "add override materials". Then "show in element viewer - model". look for "Octoling girl teamcolour" and right click. go to "float" and type "$alpha" and the hair should disappear. then with your desired hairstyle just attach the two bip_heads as you would when attaching clothes, slide the Zero slider, and boom, agent 8 hairstyles :D