At the bottom of the box you reply in , there's a tab says upload a file (in between "post reply" and "more options") Have you tried using that? Should open a dialogue box in the window which then allows you to choose which file to upload from your computer.
Looks like it could be Howdens Saponetta Cream. Find a local branch and take yours in. If not I'm sure that Apex Doors or similar would be able to match it. They make vinyl wrap doors.