Am 09.10.2018 um 08:05 schrieb Thomas Schneider:
> I am preparing a paper for PNAS. The PNAS class file pnas-new.cls has
> \RequirePackage{xcolor}.
\PassOptionsToPackage{table}{xcolor}
\documentclass{pnas-new}
or simply
\documentclass[table]{pnas-new}
Herbert