David,
Good observation. Most of the lower pitchers were in shaded area. The picture no 6 (label as RLS3) get more sun light because it was located a little higher then those basals.
Nepnut,
Sorry to disappoint you. I think picture 6 should be dark maroon because I found a xTrichocarpa with maroon lip and speckle near this plant. Remember this picture?

It inherit the speckle from the Amp so I assumed that the maroon lip is also inherit from the Amp as well. Don't give up hope so soon mah. I never have experience growing this amp yet so I don't know what it will be. Whatever will be.. will be..
I've seen brown lip N Mirabilis and all of the pitcher comes with brown lips or green lip. No sign of pink or red lip.

So I think the brown lip may be a totally different variant.

The Kuchingensis I posted last time also same, only brown lip pitchers. Remember this picture?

Anyway, I may be wrong too. Just wishing and hoping too much..