I uses masque and used Elkano's Buff Bars but never found an option to change the appearance of EBB using masque.
As far as i could tell it was not possible - but then again i didnt bother doing to much to find out.
Weak Auras i have never used, so there i am clueless.
not that im aware off, however you can use something like Clean Icons (big download, but takes up 0 addon memory as its not really an addon) which is basicly a massive file full of reskined icons