Hmmm... If I am not mistaken, the rules say to have a painted team. ... I guess the rationale is, if everybody showed up with bare metal, it would make it hard to identify the players.
There is a nominal "3 colour minimum" ... But spray canning them brown would probably do.
... If more time, you could black wash and top highlight with a white dry brush. Both of those techniques are dead quick and give surprising good results.
... Then if you painted the bases green, you'd have a reasonable looking team #Bodgetastic