all gradients are divided and not smooth..

Does this image show as a smooth gradient or do you see banding ?

If you see the whole range with no banding then there's nothing wrong with your display 🙂

All four of your images look perfectly normal to me ...

In System Preferences/Displays do you have "Millions" set for colors ?

Looking at your post, this was at first the exact situation my wife is experiencing. She just bought a brand new 15" MacBook Pro, but last year's model. At first, her desktop looked great, then, it started to look almost like it was set to 256 colors instead of Millions, yet it IS set to millions. None of the screenshots posted here look bad on my 24" iMac. I'll have to try a screen shot of her's and send it to my iMac and see if it looks good or bad. I did create a new user, and the desktop DID look better, but not quite as good as it should. Then I log out, and log in as her, and it really is bad. And what is really strange, is that the icons for folders on the desktop look OK, but the desktop picture looks real bad, AND her mouse pointer arrow is double sized and looks pixelated, as well as the spinning beachball. Yet, repairing permissions has been done multiple times, and I have run Utes twice no, with no problem found. She did use set-up/migration to move from a G4 Powerbook to the MacBook Pro last week. But at first all looked great. Then as she was re-setting preferences to suit her needs, the display all of a sudden looked really wonky.

Go to the Displays settings in the System Preferences and make sure everything is set for maximum resolution. You might also try selecting different calibration profiles and see how they look, or calibrate the display manually and set your own profile.

Otherwise, if you actually do have banding (as opposed to just a gradient, which is a common characteristic of TN panels), you may have a defective display.

Well, I checked all of that stuff before posting here. I also created a new user, and it was much better, but still didn't have that nice hi res look. More so than banding, it looks more like what a gif does when you take it from 256 colors down to 128 or less. I'll try to get a screenshot when she's done with it for the night.

We have two MBPs here and the display quality on both is quite good. If you have degraded video that can't be corrected by user settings, then I'd say defective hardware would be about the only thing that would account for it.

It's odd that the desktop picture, and the spinning beachball look bad, but the icon and the dock look OK.

An image used as the desktop background will look pixelated if the original file is too small to be stretched to fit the desktop effectively. If the spinning beach ball looks bad, however, that sounds more like a video processing problem, which might implicate the GPU, in which case I would expect to see problems with other video as well.

Well, the desktop picture in question is one of the standard Apple ones, not a user pic. The same one looks stunning on my 24"iMac. She's only had it for about 3 weeks, so maybe she should just take it back and get a different one.

She's only had it for about 3 weeks, so maybe she should just take it back and get a different one.

I agree. In your case, it sounds like defective hardware.

OK, I found it! Operator error LOL Somehow, she had changed the contrast from normal to high in the Universal Access prefs. I am surprised I didn't notice that before.