That would be 255/198/0 ... but I've used and brown/red tint once letters (and logo) get far away (and thus darker).

One thing I've noticed about optically composited text (be it credits or the crawl) is the fact, that saturation gets much stronger when something fades out. So that's what I did with the title cards as well - the green of the Lucasfilm logo gets a darker but much more saturated green while it fades out and the "A long time ago" card gets a dark, but very saturated blue during the fade. And the same goes for the receding logo and crawl as well (with yellow not getting a "darker, more saturated yellow", which would just look dirty, but a reddish/brown instead).

Also rounding off the contours of text is an important factor.