Ray,
I think the combo on Dale's Speedster with the addition of the over-riders makes it the most accurate replication I've seen. I would also recommend the Silver used on Brooks Waltons' and Stan Galat's IM Speedsters/ So, with my ruby that covers the basic red, black silver.
I was very close to picking a more retro color and there are three that were on my list. Stone Grey is a beautiful color that reflects in light as a taupe/light cocoa, and shows a light moss green in the shade. There are some examples of this color on IMs... I think Scott Sloan's 56 Club Racer Replica IM is probably the best to look at, by far. You can also find it on real steel on a clone GT in the 356R owners list on-line (57 ownend by Alex F.), a twin grille roadtser seen at the Camp Out, Ventura, and Dana Pt Pics, and a beautiful T-1 that John Leader has captured pics of. I love this color and it was a coin toss between it and the Ruby. Scott's interior would be my choice with Stone, but I have seen an original with the red Dale Bates used and it looks very nice. I have also seen a Roadster with a sea foam green interior with the stone and it is a very retro and classy look.
Another great color is Slate Grey. Look at John Leaders JPS GT Carerra. It is a deep thick color with a retro look. I have seen a pic of this paint on a real 57 with full trim and deep red interior, a stunning car... especially using Roadster Seats like Dale's. John uses a beautiful deep wine leather and his GT is one of the most unique and beautiful 356R cars you will ever see.
The third color can be found on Dan Palmquist's beautiful IM Roadtser (Vert D). It is a creamy yellow (Dan can fill you in on the code) that was inspired by Rick Davis' ultra retro IM Speedster. That paint gives the car a retro look even as the paint is drying.
If you like blue, then the color I like the best is OZ Abregov's deep blue IM Speedster. It is a beautiful car and with the tan interior... well, it exudes class. I have seen an IM Speedster in that blue with a wine interior, blue top, 2332, 901, etc... and that car still captures my thoughts. It was delivered to a customer in the Bay area. Ask Henry. I believe Wilhoits Restorations is finishing a blue Speedster now in that 'Azure Blue'.... a very nice color.
In a black Roadtser... I would copy Bill Steele's Roadster to the T, including the interior and all options, with some Bivens wheels, or the So Cal Discs like on Scott's Speedster with Super Caps.
Henry has files of pics of many colors.... check with HR. If you can accept large files I have most of what Henry sent me on a CD.
Good Luck. And yes, I love the Ruby. I swore I would not have a red car... but the Ruby spoke to me. I have no regrets.
Interior Combos.... look at all of the cars I listed. I think Dan Millers new IM has the same colors as OZ's Speedster... a very nice car.
My last suggestion: Go to all the sites... start with the 356R and go to regional clubs, restorers, etc, and look at event pics. Send Henry pics of cars you like... and start narrowing it down from there.