So hey whats up? I'm no sure if this belongs here but since I do have a fox character I assumed that this would be a appropriate place.
Colour: So first off lets talk colour, what comes to mind when you think of a fox? Probably a Red or Arctic perhaps a Fennec (those tiny little things are adorable) but were you aware Reds don't even have to be red? Now I can't tell you what to do since my fox character is a.... well.... red Red fox but maybe take a look at these?
(If the thing wont work Image can be found here
http://skinnedfawxtaxidermy.deviantart.com/art/Red-Fox-Pelt-Chart-287427571)
(link
http://skinnedfawxtaxidermy.deviantart.com/art/The-Awesome-Colorations-of-the-Vulpes-Vulpes-345664572)
Now naturally some of these colours simply are not possible in the basic feral heart engine but you know? just to put it out there your red can totally be golden or black. Now there is not much more I can actually say here other than encouraging you to look into it yourself and that if you're into genetics it's pretty intresting stuff.
Behavior: Since I'm mostly talking about Reds then I stick with them here. Reds tend to live in family groups called skulks composed of two parents, their grown young and new kits. Four to six kits tend to be the average but up to thirteen have been observed, larger litters tend to happen in regions where high infant mortality is common. Kits are helpless for about 2-3 weeks and during this time their mother will not leave them and is fed by males or non-breeding females. and at about 3-4 weeks they start exploring outside the den. Skulks tend to have about two submissive individuals but up to eight have been observed. An adult will only leave it's parents skulk if they have a high chance of establishing a territory of their own, foxes live about five years and reach sexual maturity at about a year.
Like wolves male foxes mark out a territory and every thing in it via spraying urine and have up to twelve different urination postures to ensure accurate spraying. They only really live in burrows when kits are present, when there are none they wander the territory freely. Red foxes tend to not get along with almost any other kind of animal they're kinda snappy and tend to be aggressive.
Body language: "Red fox body language consists of movements of the ears, tail and postures, with their body markings emphasising certain gestures. Postures can be divided into aggressive/dominant and fearful/submissive categories. Some postures may blend the two together.
Inquisitive foxes will rotate and flick their ears whilst sniffing. Playful individuals will perk their ears and rise on their hind legs. Male foxes courting females, or after successfully evicting intruders, will turn their ears outwardly, and raise their tails in a horizontal position, with the tips raised upward. When afraid, red foxes grin in submission, arching their backs, curving their bodies, crouching their legs and lashing their tails back and forth with their ears pointing backwards and pressed against their skulls. When merely expressing submission to a dominant animal, the posture is similar, but without arching the back or curving the body. Submissive foxes will approach dominant animals in a low posture, so that their muzzles reach up in greeting. When two evenly matched foxes confront each other over food, they approach each other sideways and push against each other's flanks, betraying a mixture of fear and aggression through lashing tails and arched backs without crouching and pulling their ears back without flattening them against their skulls. When launching an assertive attack, red foxes approach directly rather than sideways, with their tails aloft and their ears rotated sideways. During such fights, red foxes will stand on each other's upper bodies with their forelegs, using open mouthed threats. Such fights typically only occur among juveniles or adults of the same sex." Wikipedia
Maybe I'll tack more on here later but for now this is the pertinent information on Red Foxes.