This is a little bit misleading.
What do you mean by "actual" color? The color of the shell before it is dyed by Horween? Well, you know what that is, that's undyed shell. It's light tan. I saw thousands of undyed shells at Horween last week.
Or do you mean the way Color #8 looks when it goes out the door at Horween? Color #8 shell is very dark burgundy when it goes out the door at Horween. Again, I saw it last week. I handled several Color #8 shells. They're super dark and a very deep burgundy. Alden's finish makes Color #8 look a little bit more purple, more like eggplant, but Color #8 shell is definitely not chocolate brown or brown at all (like that blog post about windowsill-lightening the color #8 wingtip boots) when it is finished at Horween.
It's actually exactly correct. Alden obtains #8 shell, in its actual color, from Horween (the same color as AE's burgundy shell). They then paint the shoes with the purple eggplant dye, post construction. They often don't even bother to paint the tongue where the laces cover on their bluchers. The purple paint is the first to burn off from exposure to the sun leaving a shoe in the actual color of #8 shell - people call this "patina", but it's really just the degradation of Alden's eggplant paint.
You're correct that additional exposure will further mute the color, but that takes a good while - the eggplant goes away relatively quickly. Someone took a pair of AE's through the process and documented it with pictures. They ended up more cherry than plain brown.