Photoshop: change colour of animal fur

Question

I'm trying to change the colour of animal fur to make it look natural, as if the fur has actually grown/been dyed that colour. I've tried a colour layer with various blend modes, hue/saturation layer and a gradient map. They all work ok, but the effect isn't quite right. It's easy to get light colours that looks painted over, but I'd rather have a dark colour that just retains the texture of what's underneath.

This is what I'm trying to achieve, with shapes that look vaguely like letters:

• best example of cat that says 'cat' on it: http://www.shareably.net/wp-content/uploads/2015/01/unique_cat_fur_23.jpg
• http://static.boredpanda.com/blog/wp-content/uploads/2014/07/unusual-animal-markings-60.jpg
• http://static.boredpanda.com/blog/wp-content/uploads/2014/07/unusual-animal-markings-41.jpg
• http://static.boredpanda.com/blog/wp-content/uploads/2014/07/unusual-animal-markings-51.jpg

Here's examples of what I've done so far.

Blended colour layer

Hue/saturation adjustment layer

Gradient map adjustment layer

Gradient map on a darker original fur - hard to get the fur white like it is on the top of the donkey. It looks more like a shaved/spray painted patch than its real fur.,,,

Originals:

Answer 1

A few things at work here:

First off in your sheep picture, and any of these it works best with a two tone animal to begin with. Your sheep does have that but its the dark ears, using some third color won't look legit at all. So use that.

Now as far as the technique goes I'd use Frequency Separation and then brush it in. Frequency Separation will separate your color from your texture, any layer you put between the two affects color. So without too much effort you can do this:

Also pay attention to the perspective and the edges. I wanted the heart to look at least somewhat real so it follows the body a bit. And honestly could do it even more with some additional dodging and burning or possibly a displacement map. But at least the shape follows the body.

Then the edges aren't perfect. The colors come in and out to enhance the effect:

There you have it, before and after: