Hi, Mike.
The style, screen layout and color, as far as I am aware is set by vBulletin. As far as I know there are only two visual options the Default Style - which I guess you are using, and the Mobile Style. The Mobile Style shows up much larger on a PC screen and has larger, clearer icons from the limited glance I took at it. You can access the style selection at the bottom left of the forum screen. I was able to exit the Mobile Screen only by using the 'Back Arrow' - I could not find any other way of getting away back to the standard screen so - if you try it - be warned. It is very different from our standard screen but may help you. Incidentally using your resolution, on my system, the difference in color between the New Posts and No New Posts icons are quite clear. You may be able to enhance your colors by using your video card controller (Saturation and Hue being my initial suggestion)
HTH.
Ken.