Answers for question 1:

Firstly, Antonymy is the term that refers to two lexical forms that with opposite meanings, and there are two kinds of antonyms which are gradable and non-gradable antonyms.

For example, gradable: young/old, fast/ slow ,thinner, fatter.
           
             non- gradable: dead/alive , single/ married.


Answers for question 2:

First,  Homophony refers to two/more words with same pronunciation but different meanings.

For example, meat- meet, bare- bear , sew-so


but, homonymy is two/ more unrelated meanings but with the same lexical form.

example, bank

Answers for question 3:

The conceptual meaning for laptop should be a personal computer which can be use on the upper side of the thighs of a seated person.
The associative meanings can be related to words like mouse, hard disk and Microsoft windows system.
     

Answers for question 4:

 The hypernym should be "colors" of course !