These days? I dont know about that, Ive been making them for quite some time. It's not about color for me. Most of mine have been bamboo/osage/osage... or bamboo/yew/yew with matching handle wood. I don't like them to look too busy.
Three lams is just a really good balance... With three lams, they're thin enough to bend into a wide variety of profiles... yet with three lams, the belly lam is thick enough that tillering and/or weight reduction can be done without it getting so thin that it compromises its ability to resist compression resistance, or so thin that we'll scrape through into the glue line.... harder to do/avoid with 4 or 5 lams. That said, part of the beauty of trilams and such is that we CAN, potentially, bring them to exacting thickness and tapers and get very close to good tiller and target weight right off the form... predictability... reaping a few of the multilam build benefits without the glass.
I still make as many 'bi-lams' or backed bows as tri-lams... and more selfbows than all others combined, but I really enjoy the trilam builds for some reason. They're some of the best looking and best shooting bows I've made.
As far as this site, it could be that it's just something new to many of the folks here, and Roy's been posting a few tri-lam builds.... monkey see, monkey do perhaps?