screen color issue - not getting smooth color

i am using DX9 renderer in Panda 181 or 191.
although my screen is with true color, i see the output color of Panda being not smooth (very obvious), looks like high color or less. while in some other 3D programs i made i get smoother color.
anyone has similar feeling?

Could you show a screenshot? What do you mean exactly? Do you mean you’re seeing dithering?

in panda1.png , there is a big brown part, which is untextured, with only polygon color.
i see the transition from bright color to dark color being not smooth.
or is that the normal result with 32bit color? or it’s a problem with my LCD monitor or the Intel graphics chip.

panda2.png shows a “sky plane” with fog. i see horizontal “ribbons” in the sky, which is quite obvious to me.

other.png shows a skyplane with fog, rendered with other engine. sometimes i felt the “ribbons” being less obvious, but it could be caused by different fog parameter or screen color was affected by real world environment light so i could not judge the color precisely.

Well, all of these are 32-bit color images. I do see some vague banding artifacts in panda2.png, but I see the same banding artifacts in other.png. They only seem to differ because the fog parameters are different.