You can !
to alter any new geometry , you alter the attrubutes ( color, levels, linetype etc. ) before you create them
to alter existing entities,
1- R-Click on the attribute ( lower toolbar )
2- select the entities
3- accept the selection ( big green dot )
4- select the "change to" attributes (opens dialog box )
items 1- & 2- can also be done in reverse order ( depending on system config settings )