You have bought an emerse grown Lim. Sess. - and the new growth is the submersed version. So your plant look exactly as it should.
The roots appearing from the stem is very normal, too. If you do not like them, cut them off. The plant will not be damaged by this.
The faint orange colour of new growth, tell that your plant is getting sufficient light....... and a bit more, so it is getting "a sun tan". This will not harm the plant either.
Lim. Sess. is very adaptable to different water qualities and light intensities and furthermore a quite fast grower (which is probaply why it was recommended, since this will help your aquarium cycle and mature). Lim. Sess. tends to grow a bit "leggy", because of the long internodes between sets of leaves. The fast growth means, you will have to trim the plant quite often. you cut the longest stems quite low and the short remaining stem will grow new shoots. If desired, you can re-plant some of the offcuts next to the original plant to make the group more dense (or plant elsewhere). Remove lowest set of leaves and stick the bare part of stem into your bottom layer. Roots will soon be produced and the new plant will grow happily on.
Good luck - you will love this plant.......