I have researched silk tops on this forum and the internet and have some questions

(im useless)
I saw ladies on here talking about how they order their silk tops 1/4 an inch 'back' or 1/2 an inch 'back' and I'm confused, surely if you order a silk top and its not right at the hairline then it wont hide the knots at the hairline because it will be 1/2 or 1/4 inch back from it? Is that what they're talking about?
Also, if ordering transparent lace do I have to tell them what color to make the silk top? or will it just be obvious to do it light colored or are their lighter colored 'light colors' lol I also saw that some ladies were talking about whether they get a single layer of silk or double layered silk etc. I want single so that its thin and doesnt have a line of demarcation from bumping up from my skin. Do I have to state '1 layer'?
I am hoping to order from 'Enoya lace wigs' but am confused with their website. There's not much information for me to send my specifications for a quote?
They don't seem to have a color chart,
silk color chart (which is why I asked if they just automatically have one light color to match transparent lace?)
So I'm not sure what color to say when contacting them about my wig (every vendor with a color chart Ive seen has different colors) or what to say about this silk top really. I want to know exactly what Im ordering and getting etc
This is their website so that you can see what I mean: http://enoya.en.alibaba.com/