staining fiberglass

How do I get Permacast Fiberglass columns - Roughsawn - to look like stained cedar? .hbgcolumns.com/products/permacast-roughsawn/#product-tabs-sections Instructions say to use a solid stain or a paint, but the pictures on their website show a real looking cedar finish. How do I accomplish...

Have a customer who tried to stain his fiberglass door with Minwax Gel stain. Came out very splottchy and uneven. I tried to touch it up but that makes it worse looking. Anyone have any experience with redoing a fiber door? Does it need to be stripped and started over? Thanks for any tips...