(Defun c:bt0(/ToZero aDoc blk blocks layers ab cd)(vl load com)[color=“blue”](Defun ToZero(bn)(vlax for itm bn(if(and(eq(vla get ObjectName itm)“AcDbBlockReference”)(not(member(setq ef(vla get eficivename itm))llst))(progn(ToZero(vla item blocks ef))(setq llst(cons ef llst)))(vla put layer itm“0”)(vla put color itm acByLayer);