I am now working on an system but ho do I need to ask for the user details, now I have done like for an topic (adding "user_name" and "user_colour" in the table, but what if the users color changes I thaught it was something in the acp when changing the users default group. But how I do it best because if i put the name and the colour code in the table and the users default group changes the color is wrong

So what can i do the best if I won't change so less as possible files in the ACP and my systems load time must be also so low as possible... Is it possible to easy ask all user details with an user_id orso or need i to make an resync module for the acp?