Sure.

I've even run Shimano pedals on Campagnolo cranks, and ridden Campagnolo gruppos while wearing jerseys with SRAM logos.

I do make sure the result is attractive. Regardless of manufacturer I avoid black anodized components which look bad with silver scratches and imitate carbon fiber the way laminated plastic flooring pretends to be wood, and even swapped the inner cage plate of my Record rear derailleur for a silver one.