I have attached the extract sheet that came with it from more beer.
Not a lot of additional information.
The recipe didn't state if dry or liquid malt extract was used (it's one of the main factors in color when brewing with 'extract').
I also didn't see where SRM was listed. I'm of the opinion that some models to calculate SRM with extract are simply wrong - they calculate a value that's too light.
@CascadesBrewer offers some good observations.
Boil time is another factor for managing color with 'extract'. These kits had 60 and 90 minute boils. I limit boils with DME to 30 minutes and get beer colors appropriate for the style.
Many brewers will modify kits to do what's called "late additions of extract". Put 25% to 50% of the extract at the start of the boil and the rest at "the end" of the boil (sometimes with 15 minutes left in the boil, sometimes at "flame-out"). The book,
How To Brew, 4e is an excellent source of information on this technique.
Changes in boil time or in the timing of extracts will impact estimated IBUs, so it may be desirable to adjust the timing and amount of hop additions.
What else will I need to go all grain.
Going all grain is a great way to get control of color in your beer. Given that you are already kegging, and you are interested in color control, it seems like a logical step.