I'm trying to upgrade a texture pack that is no longer supported by the original creator. Unfortunately, I'm having an issue with some of the entities. The Spiders and Endermen appear to be slightly white; I can see some of the underlying texture, but the coloration is wrong.
I really wish people would use a search engine before posting. This problem has been around since... whenever Minecraft entered Beta. Yup, that long ago. And the answer is still the same.
The problem comes from the overlays used for the eyes. What you may not realize is that those overlays cover the entire body of the creature, not just one face. What's more, those layers don't use the transparency that you've set for them. They just disregard it entirely using whatever the underlying color is. So why white? Well, some image editors fill their 100% transparent spaces with black while others use white. Supposedly each has their advantages, but in this case white is distinctly detrimental to what you're trying to accomplish.
So how do you fix this? Well, you could open the eyes overlays in a program that encodes black transparency like Photoshop... or you could take the much better route and just bucket-fill all of that transparent space with solid black. Minecraft disregards your transparency anyway so why not just make the game's job easier? Ditch the alpha channel yourself by making the entire image opaque! That way you have full control over it without the need to struggle with invisible pixels.
Thanks for your help! This was a pre-existing set of textures, that had worked in older versions of the game. I thought that something may have a occurred when I ran the pack through the Unstitcher or TextureEnder. I had changed nothing with it myself. Incidentally I did google the issue, perhaps I constrained my keywords too much. I figured it might have something to do with the eyes, seeing that most of the other entities in the resource pack worked fine after converting from the texture pack.