In addition to the other feathers mentioned remember that marabou comes from turkeys. Especially the feathers just behind the legs and underneath the wings.
If you try to dye them darker you will have sucess, but since they start out brown, don't expect to get vibrant colors. The good news is that the chocalate brown is a very useful color.
Ed
" Fishermen, hunters, wood choppers, and others,
spending their lives in the fields and woods,
in a peculiar sense a part of Nature themselves,
are often in a more favorable mood for observing her,
in the intervals of their pursuits,
than philosophers or poets even,
who approach her with expectation."
Henry David Thoreau