Blotchy Darkened Dye

[troop]

have a question regarding the darkening of my holster after casing. i am using W/C holstered sides in russet. i dye it with feibings pro oil dark brown. sometimes i will airbrush the edges in black. afer it dries the color looks great. after assembling the holster i case it for about 10 seconds to a minute. wet mold it (with clean hands and tools) the problem is as it starts to dry, sometimes it will start to look burnt and blotchy, not returning to anywhere close to the color it was before casing. i will redo another holster from the same hide in the same way and it will come out perfect. any ideas of what is happening and if it can be prevented would be awsome. thanks

Tony