White screen may display slightly cooler (bluish) tone in the middle and slightly warmer (pinkish) tone at both sides. When you move your head from side to side the cooler zone moves accordingly - the warmer tone changes into cooler one. So this is a part of a general viewing angle issue. This is not a defect of the monitor.
It’s present, but nothing to worry about – it’s just mild. Also it’s better after calibration. One can get used to it very soon. Actually, by the end of the test I lost it.

Backlight flickering is present on this monitor (same for any monitor with CCFL backlight; this is not CRT-like flickering) but it is not visible for a naked eye. Flickering can be detected with the use of a digital still camera. The lower the brightness setting on the monitor the more flickering. Comfortable low brightness settings of a monitor are necessary to protect our vision. At 130-140 cd/m2 (good for a longer work in well lit environment) photo camera shows bad flickering. Some people believe this effect worsens eyestrain. The good news is that flickering on the Dell 2408 is gone at higher brightness. But our vision cannot tolerate this high level of brightness for the office work. So…
The Dell 2408 has been tested with the monitor brightness control set to 100% and video adapter brightness adjusted to very low so that in the result we have a desirable number of cd/m2 on the screen.
Result: no flickering!
Please watch the first part of the video supplement.

Actually flickering (for both wide gamut 2407-HC and 2408) has its specific pattern – white sparks alternate with greenish sparks. You can see that on the flickering video test if you stop the video and watch frame after frame. Then look at another part of the flickering video test, where brightness control on the monitor is set to high and flickering is gone. See frame after frame – they all are white, no more greenish sparks.
This is a possible explanation for why some people are able to catch “DLP rainbow effect” at lower brightness and nothing at higher brightness.
DLP rainbow effect is nothing but splitting hair. It cannot be found unless you deliberately look for it. In order to see it you have to move a white cursor on a black background and follow the cursor closely with your eyes and head motion. Don’t bother yourself, forget it.