Awesome to hear, Rodney. Have fun with the sander. Be sure to take some before and after photos. You'll have them for all time to remind you of the good work you did. :-)
HI, Rodney. The Sikkens may have a little bit of pigment in it, but not a lot. You could add more pigment, but it will likely affect the transparency of the stain. Sanding and cleaning will certainly help you get a good foundation, which is the most important factor to any stain's longevity. That said, a light stain is always going to wear away sooner than a darker one. I would hate for you to lose your money, too...I would suggest giving a call to the Sikkens folks for a couple reasons: 1) find out if you can add pigment without affecting the performance of the stain; and 2) ensure the stain you still have is still good. There is a shelf life to products and every manufacturer will have a different limit. You might not want to use that stain anyhow.
If Sikkens says all is good to go and you can add some pigment, I'd suggest you do that. If you can't, but the stain is still good to use, do your good prep and use the stain. Make sure you throroughly mix it. Use a squirrel cage type attachment on the end of a drill and scrape all pigments off the bottom of the pail. Mix throughout staining, every 10-15 min. You may find that the color will be darker going that way anyhow. If nothing else, you'll hopefully get another 1-2 years out of it and didn't totally lose your money.
Hope that helps!