Help desciphering steps in Florence Backpack

[PurplePlushFox]

I'm making Hopefulhoney's Florence backpack, and had a few questions on the instructions. 

Rnd 1: Attach B yarn (still double stranded) right in
the back, and towards the middle of the base –
working from the outside of the backpack. Ch 1,
blsc in the same st. Blsc in next 77 sts along
border of “Base”. Do not sl st in 1st st of this rnd.
(78 sts)
Rnd 2: Start crocheting in 1st st from the previous
rnd. 1 f in next 78 sts in “A”. Do not sl st in 1st st of
this rnd. (78 sts)
Rnd 3: Start crocheting in 1st st from the previous
rnd. *1 f in next 2 sts in “B”. 1 f in next st in “A”.
Repeat from the * 25 more times. Do not sl st in 1st
st of this rnd. (78 sts)

For round 2, is it supposed to say it's the "B" color? That makes the most sense but I'm new to crochet.

Additionally, I can't tell if the main body color is supposed to be double stranded as well. I'd imagine so, as the picture appears to have the same width, but I can't be certain in my ability to notice the details.  You can find the pattern here. I'm sorry if this post is weirdly formatted, I've never made a forum post before.

[Granny Square]

Welcome to the 'ville!

Just checking because the technique used to make the oval bottom is a cause of a lot of questions here (because it is unusual to work around both sides of the chain, which makes the oval.  So you have that part done in color B (blue in the photo).

Color B is used for the base, and it appears that it tells you to fasten it off, and re-attach it in a different spot to start the next section, which is not that uncommon either.  It is probably to have the 'seam' in a better looking spot than it would have been otherwise.

It appears that the whole backpack (except the drawstring) is made with 2 strands, which makes sense as you want a backpack to be stiff and sturdy.