Well, strictly speaking, that's a model C F/A-18 (see the digital fuel indicator). We modeled an A so, no color displays on that one.
Unfortunately, it's not very easy to replace F/A-18 gauges. Mostly because we have the user interface modeled in 3d with actual custom events that works only with the official F/A-18 gauges, and the gauges who provide the display, but also a lot of the logic. The VC is really too much intertwined with the gauges, that's is very difficult to simply replace a gauge with another one.
Also, the 4 different displays (3 DDI + 1 HUD ) are not even different gauges: it's just a single gauge that simply displays 4 different pages depending on its internal state and the actual pages are not even in the gauges, but in the main airplane logic. That's (one) of the reasons it also performs so surprisingly well, all considering. But is not really designed to be expanded easily.
