Ugg sizes and colors?

So I have 2 questions the first one is I went to buy Uggs from Lord and Taylor. And I asked the lady if I could try on a size 6 in kids. So she brought out a 5 and a 7 she said they didn't have 6 so I tried on the 5 and they fit fine they were just a little tight. And i tried on the 7's and they felt really loose and stuff. And the lady was like oh they fit PERFECT!!! Don't go with a size 6 this is your size... And I'm thinking she was just saying that because they size 6's are like 40 dollars cheaper. So I'm gonna buy them online because she creeped me out. And I'm gonna get 6's in kids. Are kids uggs any different from adult uggs? Also I'm thinking of getting either the tan/chesnut colored one or the chocolate ones... Which do you prefer?? Thanks!!!