There should be a thick line at the top and a thin line at the bottom.
There is no standard for exactly how thick these lines should be.
This page uses a 4pt top line and a 2.5pt bottom line.
Because swiss design was meant for print publishing it makes sense to use points.
Points are defined in inches, so it is easy to be precise wihout using ugly numbers like 1.6667".
If you can't use the color in a sentence you're doing it wrong.
If you must resort to using hex codes for colors, try only using the first 3 digits (#FFFFFF → #FFF).