Curious negative colour (OrthoLitho) ... ?

Attached is an image of two negatives on my lightbox.

I've adjusted this picture on my (calibrated) monitor to as close as I can manage to what I see with my naked eye.

Both negatives were exposed a few minutes apart in almost identical lighting.

On the right, a couple of frames of Acros at EI100 developed in D23 1:1 for 12 minutes. This is what I expect a "normal" negative to look like, at least in colour.

On the left, part of a 5x4 sheet of Arista OrthoLitho at EI1½ developed in D23 1:14 for ~10 minutes (developed by inspection). It however has this - to me - rather odd gold or bronzed appearance. I presume the colour is as a result of the size and/or shape of silver particles.

I haven't tried contacting it on normal paper, by the way, as this is part of a few tests towards producing 10x8s for Cyanotypes etc. Cyanotypes made with these "golden" negatives look OK to my unpractised eye.

I've got this effect on all the OrthoLitho I've tried in this developer at this dilution so far, at various EI from 3 to 0.375, fresh film, purchased this year

Fixing for longer or in absolutely fresh fixer or in absolutely fresh fixer for longer doesn't change the colour.

So, the question is, why the peculiar colour of the OrthoLitho?

Or is this "normal" for this film?

Or is it an artefact brought about by the highly dilute developer?

Or what?

No advice is being sought about what film and developer I "ought" to be using, by the way.

Perhaps insufficient washing?

very thoroughly washed as are all my working negatives

I've shot this ortho film in 4x5 and I don't get this brown tint with xtol, hc110, or diluted dektol. It looks almost like a negative that was developed using a staining developer. It shouldn't have any effect on prints unless it's very yellow or orangey and your using vc paper.

From cursory looks at what this film does, many folks seem to expose it at EI 6-20. Since your negative was strongly exposed yet shows pretty normal contrast, I would assume that you pull developed it. D-23 is a very fine grain developer, and you pull developed, together you must have extremely fine grain which can be yellow.

As it doesn't appear to be a fixing issue I have to assume it's a result of the grain size too. But I'm interested in the mechanism of how it's occurred - as I understand things, D23 is very fine-grain by dint of the large amount of sulfite it contains, but on the other hand in this case it is extremely dilute, which would bring the sulfite concentration down a long way, well below the optimum that's often quoted for solvent developers.

I really must shoot another test set and try it in another developer, of course.

I found that EIs above 3 simply didn't give me sufficient shadow detail, and EIs lower than 11/2 didn't offer any advantages. But when I was reading around prior to deciding to have a go with this stuff, I have to say I didn't find anyone exposing for continuous tone at the EIs you mention, Rudeofus. But then it wouldn't be the first time people have looked and found different things about a subject.

If you use D-23 1+14 for 12 minutes, you strongly underdevelop your neg, which means you get reduced film speed and contrast together with small grains. You can do a simple test to find out if it's small silver grains that give you the yellow tone: use some left over C41/E6/RA4 BLIX on a test clip and see whether the yellow stuff disappears. Since these BLIXes are near neutral (pH 6.5), they should preserve any developer stain (if it exists) but should quickly remove all silver.