when wotking on the qeust with ZQeust the dungeon floor had the right color. but when testing it sudently changed into cset 0.
i dont know if this info is helpful but the tileset i'm using is extracted from 2.10test.
automatic cset change
You set the color on the dmap
thanks another for solving another mistake by my side.
as long as i kearn from them i'l be fine.