Hi a question about copying a web site design?

[bill]

Hi I am a amatuer web designer working in web design company and I was wondering if you surf the web , you visit sites and like their design and set up are you allow to built a site of your own copying the other web sites design. I don't mean copying exactly pixel for pixel / code for code but very close different colors and minor changes to design.. is this legal or does it break some standard of web designs?

[SeungHild]