PIne isnt a wood species that darkens much with age, so that is not a
problem. A coat of polyurethane will do a lot towards making it keep its nice
look. Since pine is notorious at sucking up finishes, I suggest you use a
Zinnzer sealer/coat and then apply the finishing coat. Rub out the final with
wax and 0000 steel wood and you will have a nice finish. If you use a wax with
stain (Woodcraft), it will have a nice, older looking finish.