Assuming the construction of your 4Runner gauge cluster is the same as a similar-vintage Tacoma ... (I know about Tacos, but I'm not sure about 4Runners....)

Yes, you can remove the cluster from the dash and replace the bulbs to get an alternative illumination color. In 1995.5 - 2004 Tacomas the cluster face has pretty much transparent 'slots' through which the bulbs' light shines as whatever color the bulbs are. In other words - the face doesn't affect the color.

You can go with colored bulbs or bulb 'condoms' (colored slip-on covers).

The one problem reported in using LED's for (Tacoma, at least...) cluster color change is that they shine in a more focused pattern than the OEM incandescents. This can result in 'hot spots' (areas of brighter / lesser illumination) from side-to-side or top-to-bottom.
From what I gather, this 'hot spot' issue varies among different brands of LED bulbs.

 

For the flickering check your fuses for the dashboard lights. My buddy had the same problem and it was a loose fuse.. solution: slightly bend the prongs in opposite direction to give it some grab.

 

EnolaGaia - I shall check out the blubs before I buy anything.

Godzilla - We checked the fuses because my Dad has a fuse thingy checker or whatever the hell it was and it was reading ok. Er I think thats what he was doing. He said they might have made the bulb get loose when they moved the alarm and all that stuff to the console.

My poor 4Runner will be torn apart for awhile. We have to try to fix the clock and the lighter thingy cause they both aren't working. I just need the lighter thing for my cell phone charger cause my battery sucks and buying a new one did nothing... I also have the old CD player in there under the new CD player. Sounds weird...

 

Amby the fuses may be a.o.k. Im just saying to check to see the tightness of the fuse in the socket. If you bend the prongs abit it will snug anything up that may have been loose. Same symptoms happened to my buddy, and this happend to me with the brake light fuse.