Chocolate Black?

[Shadow Scar]

She comes from a long line of black based belgians...born with a black coat and darkened like a normal black coat, however shes begun to lighten to more of a dark brown coat.
http://www.horseworldonline.net/horse/profile/1823404

[BlackOak2]

She comes from a long line of black based belgians...born with a black coat and darkened like a normal black coat, however shes begun to lighten to more of a dark brown coat.

This is because of the Lp varnish and bronzing. She inherited the trait from her father and you can easily see the band of snowflakes around her front leg.
She will continue to change 'color' a bit as the bronzing comes and goes and also as she continues to varnish as she ages.
She also appears to be a single cream carrier, but I'm uncertain on that.

[Silverine]

She comes from a long line of black based belgians...born with a black coat and darkened like a normal black coat, however shes begun to lighten to more of a dark brown coat.

This is because of the Lp varnish and bronzing. She inherited the trait from her father and you can easily see the band of snowflakes around her front leg.
She will continue to change 'color' a bit as the bronzing comes and goes and also as she continues to varnish as she ages.
She also appears to be a single cream carrier, but I'm uncertain on that.

Yep, black with lp complex.

However, she does not carry cream. Her foal coat is the classic reddish of a normal black. What she does display is a bit of how lp can affect the foal coat - kind of a foal varnish, if you will. This tends to show up on foals that have extreme bronzing and varnish in their lines and generally means that they will have very strong expressions of those traits - as you can see in how orange your girl is turning. Your girl's sire didn't have particularly strong varnish, but it's possible her mother is hiding some heavy varnish traits - her great grandsire on her mother's side has some pretty impressive varnish.