Fuse question 71 beetle

Hi all,
I have a 71 beetle. It has this crappy old fuse "box" under the dash. The fuses are plastic with copper of varying thicknesses in them.
Question one. Does the colour indicate amps? ie red = 10A etc?
Question two. Can you still buy those plastic fuses?
Question three. How hard to replace with something a tad more modern?

Given the current fuse box is responsible for two recent major painful experiences (one where she stopped and stayed stopped, until after foiur hours of fiddling with everything ignition wise I rotated the fuse, and hey presto, there runneth the beetle, and secondly, why won't my new wiper motor work? Oh the fuse blew!!)

I know, she is old, but generally reliable. Now can anyone answer my questions??

Always Learning!!