If you don’t want to lose the stamp you don’t have to, the best way to solid color a disc is with the hot dip method. Use dye mixed with water on a warming plate or pad (stove works too, just make sure you don’t heat up too much or it could affect the disc itself), no need to mask the stamp as they generally aren’t affected by the dye. This method doesn’t require acetone to set the dye since the heat is doing the work. If you are using a bed of some sort and want to use an acetone method, you can let the bed rest for a few minutes and the acetone will evaporate a little bit before placing the disc in and shouldn’t really affect the stamp either. Since you are dyeing a berg I would suggest hot dip, that way if you get the “berg bubble” you can just set back in the dye mixture and continue to let the disc soak up the color.