Grey and gray are just alternative spellings of the same colour. Pink, magenta and fuschia are slightly different shades.Pink is a general term for the light red colour you see on the "answer this question" button on italki. Magenta is darker. Of course I cannot really explain colours with words so here is an example http://ingridsundberg.com/2014/02/04/the-color-thesaurus/

"Gray" and "grey" are the same. BOTH spellings are used so commonly in the United States that I'm not even sure which is the "U.S. spelling." I think that in the U.S. "gray" is the "common" spelling and "grey" is the "variant." Color terminology is complicated. The distinction between "pink," "fuchsia" and "magenta" is the kind of thing artists and people who pay attention to clothing know, and are not completely standardized. However, now that the web is becoming more and more important, lists of the names of the "web colors" may be useful: https://en.wikipedia.org/wiki/Web_colors "Magenta" definitely has a little bit of blue or violet in it, and it has a special status in the graphic arts. When printing color pictures in ink, layers of ink go on top of each other, and each blocks or subtracts certain colors of light. "Magenta" is the name used for one of the three "subtractive primaries," CMYK (cyan, magenta, yellow, and black). Very roughly, "magenta" = red + blue, "cyan" = blue + green, "yellow" = red + green. If you want to make red, you overlay magenta and yellow. The magenta blocks green, the yellow blocks blue, and only the red, which is common to both, gets through.

the main difference between fucsia, magenta and pink.... it´s the intensitive of pigment.... ( a little, medium or strong).