The articles in the DB FAQs show you how to save data to a database and get it back again, which is part of your question.

In terms of selecting a colour, I recommend using the Common Dialog control (add it to your program via "Project"->"Components").


Secondly, I also wanted to know that is it necessary to have primary keys in Access database? I haven't assigned any primary key and haven't felt the need yet.
Primary keys are not essential, but as a general guideline you should only leave them out if you are certain that they will cause problems for that particular table.

There are various reasons why Primary Keys are a good idea, the main one being that they remove the possibility of having "bad" duplicate data. With PK's you cannot accidentally create two identical records (which you then can't edit/delete uniquely, you have to work with both), or two records that contain data the same data for the PK (which would indicate you have designed the table(s) or PK badly).

You can find more details in the many different articles/books that explain what a PK is.