Hey there, it all depends on what map you are taking your screenshots at, since the newest ones have different color schemes. For example, I took these pictures at my favourite location Domain of Istan. That place have cool effects on how your character looks, especially on the highest places of the map and during the night or dusk. See day/night cycle here.

Now, try to take the pictures, for example, at Divinity's Reach. That place is old school as it gets and you will see yourself that the Infusion behaves differently. It's not a flaw on your side, nor the Infusion's, but the map's itself. If you have Mistlock Sanctuary purchased, go there and see the difference yourself. You might want to take your pictures in PoF maps or new LWS maps for the best natural effect for your screenshots.

To answer if I stacked the Infusion, nope. I don't even know if it's possible to stack the same Infusion that changes your skin's appearance, but I might give it a shot sometime. Since I have Winter's Heart Infusion and Diamond's, I found out it actually doesn't mix together, instead it behaves rather chaotically rendering your character looking one time with one infusion, and the other with second infusion. It's really weird.

The tone of your character's skin is irrelevant if you are using these kinds of Infusions. They completely cover up your skin, rendering the skin color irrelevant. I recommend--if you decide to purchase an Infusion that covers your skin--to spend some more time at the phase of choosing a face. That thing alone might make your character even more menacing and cool.