>>Eventually, you could detect the video mode and recommend to the user to change it.
>
>I agree that "morally" it is improper to change a user's system setting. However, many users still don't know what's screen resolution, 256 colors or true color...
>Assuming I'm able to detect that the user's video is able to display true color, am I really left just with these options:
>
> 1. create different graphics for different color settings
> 2. recommend to the user to change it (as per your suggestion)
> 3. leave it as it is & hope for the best
>

I am always the first one to shout and grumble if any program disturbs my settings & other environment, so what I'd do in this case is to issue an alert of this kind:

"The pictures you are about to see look much better if viewed with xxx by xxxx resolution and with three zillion colors, and your video system is capable of showing them. Would you like to have these options turned on now?"

...and then present the user with choices like
"Yes;No; Yes, but put it back later;Yes, but ask me later if I want to keep it".

Now we're back to the question: what should we run if user chooses resolution change, and how do we avoid restarting Windows on older W95's?