The two I got as a gift (part of a bass assortment) are black and the deer hair isn't particularly tightly packed. The tails look to be marabou, a little dark flash, and a couple of grizzly hackle. No rabbit Zonker on these and they don't look real big, maybe 2-2.5 inches long tied on some odd looking wide gap light wire bronzed hooks.
When I went to order a few more, they give 4 different color options, black, olive, chartreuse, and purple, but don't list the size or give any option on that with this specific pattern (but list the size on every other pattern I looked at on their website). I have mostly tied my own flies and have never ordered from this pretty well known vendor, but I noticed some odd grammar and word usage about various flies to the point where it made me feel like English was the second language for whomever writes their product descriptions.
I'll probably get around to making my own. I don't have any deer body hair and have barely ever done any hair spinning and trimming. I just want to get a better feel for color before ordering a bunch of deer body hair, a packer and getting a razor.
I don't believe that color is all that important. It's the action & movement of the fly that gets the attention. I like to have light & dark colors, and those I mentioned have been good. I've seen great looking color schemes on Dalhberg style flies, and certainly appreciate the artistic part of creating them, but don't feel it's necessarily going to produce any better than keeping them simple. Those I have are as you've mentioned, marabou tail, some grizzly hackle & flash too.
I have 3 sizes, and they're tied on older Mustad Accu Point light wire hooks. I think they were sizes 2, 4 & 6, and the size 2 is closer to a 2/0 for other style hooks. That produces a fly around 3" on the size 6 & closer to 5" on the size 2.
There are versions tied with rabbit strips, and they're a good fly, but those I have are tied with fairly long marabou tails. As much as I love tying & fishing with fur strips, the marabou is a lot lighter once wet, and is easier cast with a lighter weight rod. I've used the size 2 with my 6 wt. I have tied the rabbit strip versions & they're best cast with a heavier weight rod.
I generally prefer the belly/flank hair for bass patterns, but have used back hair for Dalhbergs also. It's not supposed to stay on the surface, although tying a tighter, denser head will allow it to stay floating longer. That's why I don't get too concerned about the heads, and I know it's going to sink some anyway. I trim the heads with scissors, don't even bother with the razors.
Only thing I messed up on was not adding weed guards. But they're not a fly I like casting into really nasty snags anyway. For one, the hooks I've used are too light for that & I feel like I get better reactions when they're fished along edges in more open water areas and with fairly long, yet sharp strips that allows the fly to dart around & rise & fall with each strip.
I don't view the Dahlberg Diver as a bass bug, but more so as a streamer with a buoyant head.