what is “warm black” (paint)?
It is my understanding that warm black paint is not black yet. Still towards flat a bit if you will, as flat paint is a little grayer in lighting.
It is getting warm to the idea of being black but not quite yet.
Just like warm blue is not blue yet. But fortunately a little deeper in the hues and tones than Robin’s egg blue[Y]
Well known as medium blue but unfortunately there is no such thing as medium black.
Black is black, otherwise it’s a variation of dark gray. Unless you start talking midnight black, which is a whole complete different story.
And mind You, Foreigner had a song called Midnight Blue.
[:-^]TF
So whatcher sayin’ is that it ain’t the paint I left on the window sill this mornin’, and thet the dang sun warmed 'er up?
I woulda thunk that yer warm black paint started out blacker ‘n’ black, then sumbuddy started a-tinkerin’ wif it, an’ went’n dumped sum udder colour in der, makin’ ‘er not quite so blackish. A little bit o’ yer red paint’ll do that, I t’ink…takes da edge off 'er.
Wayne

Exactly Wayne!
Finally someone who understands[Y]
TF
I first became familiar with the term “warm black” from Paint Shop articles in Model Railroader magazine back in the 1980s when I first became interested in painting a fleet for my private roadname railroad.
I use a formula for warm black paint from one of these articles, 4 parts black, one part white, and one part red.
In figure painting I have seem the term “Warm Black” used to describe the way that pitch black looks to the eye when illuminated by a bright light in the 3,000 K temperature range. I think the chart provided by John shows this.
Pitch black illuminated by a bright 5,000 K light source will reflect neutral gray.
Following this logic, I should not be painting my locomotives warm black, because I am trying to simulate coloring in natural sunlight, which is near 5,000 K, but it looks right to me.

-Kevin
Quite a few huffs of the sheen certainly takes the vibrancy out of the equation. But kids do not try this at home[(-D]
Testors dullcote definitely works better and takes the headache out of the process for you to feel better in the morning[:-^]
[(-D][(-D] kidding ofcoarse!
TF
I would define it as being midway between dark black and grimy black. So a very dark grey, so to speak. BTW, I really like Protopaint warm black for my Canadian steam engines. It’s pretty close to what we see in the historical pictures of CN steam engines… Grimy black is probably closer to what one would have seen in the dry and dusty southwest.
Simon
Red warms, blue cools, that goes for anything in the warm or cool family. Wow I had to go way back for this one.
Source?
Rich
Wayne, I totally agree, and I would remind TF that Foreigner does not have the final word on color. AC/DC does, as expressed in Back in Black. Nowhere does it mention Back in Warm Black.
Rich
[(-D][(-D][(-D]
Rich!, You are exactly right! I have no idea what I was thinking with Midnight Blue? [(-D]
[8]Well I’m back! And I’m back in Black![8]

[(-D]TF
Too many people follow the Rolling Stones advice and just Paint It Black, when they should be more like the Greatful Dead and use a Touch Of Gray.
-Kevin
So where does Imitation Black be located on this chart?
Coffee.
PMR