What are really these electric sparks and why do they attain a characteristic color?
The bit you see is the heated air. The characterstic color is either white simply because it is hot enough to be the same temperature as the sun (or near enough for our eyes) and so looks white.
Or sometimes green because it has vapourised some of the copper wire and copper emits a green wavelength when it burns
What about blue?
Oops I was wrong.
Air isn't dense enough to give a noticeable black body emission from a plasma.
Most sparks appear white simply because they are bright enough to saturate your eye's color sense.
The blue color is from the emission lines of oxygen/nitrogen molecules in the air, but green is from the copper.
Hey mr. Whats actualy is a spark ie what composes sparks and what actualy causes sparks and why?
what i get you is that heating effect due sparking causes the characteristic color
You may want to read these two threads that have the beginnings of what may answer your questions:
Separate names with a comma.