Help with Latin translation from a 17th century ecclesiastical Latin book

Question

The book is Panoplia Clericalis, and the passage I'm having difficulty with (which I suspect is much easier than I think) is, from page 602:

De colorum mixtione, qui differunt, ex varia eorum commixtione omnis ferè generis colores fieri posse existimant.

Which looks a bit like:

As far as a mixture of colors which are different, they(?) consider that from varying mixtures colors of nearly every kind can be made.

I'm not sure who "they" are, though. I'm wondering if I could translate that by something like "they say" rather than "they consider"; the next sentence begins:

Ex caeruleo enim et flavo (aiunt) fit viridis...

That is

For from blue and yellow, they say, green can be made...

I'm imagining that "existimant" is intended to give much the same idea.

I had been questioning the occurrence of "omnis" as well but for some reason the fact that it can be a genitive form (and thus go with "generis") had slipped my mind.

Answer 1

Your translation is definitely on the right track, but there are a couple of things I want to point out:

• Omnis modifies generis; that is, omnis generis means "of every kind". There doesn't seem to be any other word than generis that omnis could match.
• Existimant doesn't have an obvious subject. The sentence you quote starts a section, so if there is an intended subject, it should be common enough in (that part of) the book to make it clear. I didn't look too far back to find such a recurring subject, but it may well be that there is none. You can translate that as "they consider", "people consider", "the practitioners of this art consider" or some passive structure like "it is considered", depending on larger context.
• I don't see a justification for the "as far as" structure you use at the beginning. Instead, qui differunt seems to be a simple relative clause modifying colorum. Since "of colors, which are different" is a bit heavy, I would go for "of different colors".
• In my reading de colorum mixtione describes a topic and ex varia [colorum] commixtione describes raw materials. To clarify this in English, some restructuring is in order. I see no particular reason to use mixtio for one and commixtio for the other; I suppose it was done for the sake of variation and both words could be used for both meanings.

These ideas lead me to this translation:

De colorum mixtione, qui differunt, ex varia eorum commixtione omnis fere generis colores fieri posse existimant.

People think the following about mixing different colors: a color of almost any kind can come from a varying mixture of them.

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If the verb is disserunt instead of differunt, we get a different interpretation. Now qui differunt does not qualify colores but is the subject of existimant. This does admittedly make the Latin sound more natural. My suggested translation in this case is:

De colorum mixtione qui disserunt, ex varia eorum commixtione omnis fere generis colores fieri posse existimant.

Those who discuss mixing different colors think that a color of almost any kind can come from a varying mixture of them.

Answer 2

.1. "They" impersonal
In this and the following page he distinguishes between quotations, which he attributes to named authors, and common knowledge which is signified by existimant, they opine; (aiunt) they say:

De colorum mixtione .....colores fieri posse existimant. (p.602 )
(aiunt)

and in the first line of the next paragraph

dictum.nemo nescit

“no-one is unaware of it being named from the flower that is called viola / violet."

Murex est piscis qui ...dicitur...habet venam quâ promanat cruor (p603)

.2. "qui differunt "
Since, in the previous paragraph, other colours are mentioned ( Viridi colore utatur // in hac enim albo utatur.)"qui differunt " could simply establish that the discussion is now moving on to other colours.

However, from the context, it is more likely that he wants to distinguish mixing, from blending, (of say two reds, or the addition of black or white to change the tone).

.3. Translation So, with a slight difference in emphasis,

De colorum mixtione, qui differunt, ex varia eorum commixtione omnis ferè generis colores fieri posse existimant.

Concerning the mixing of the colours which are distinct, they understand (estimant) that colours of almost every sort can be made from a varying (varia) mixture of them.

..which is almost exactly what you said

Answer 3

There is a transcription error. It should read "qui disserunt." "Qui disserunt" is the subject of the verb "existimant." "De ... mixtione" defines the topic of "disserunt."

"Those who have written treatments about mixing colors are of the opinion that colors of almost every sort can arise from combining them in various ways."