The phrase "all that dark" is correct and usable in written English.
It can be used to describe a situation, mood, or atmosphere that is particularly gloomy or negative.
Example: "The sky was filled with ominous clouds, and the air felt heavy with all that dark."
Alternatives: "so much darkness" or "all this gloom".
It turns out that night in New York isn't all that dark.
The evening looks, with a flutter at the hem and sometime a pavé of blue stones on top, were serene, while all that dark nomadic romance surrounding a nice Armani jacket seemed to contain a sting, like a scorpion's tail.
"Well, there's an aesthetic pleasure in colonial style – all that dark mahogany and wickerwork is lovely and it's rather silly, I think, to condemn those who enjoy all that.
Despite all that, Dark Funeral was clearly the fans' favorite: if metalheads want black metal unsullied by prog-rock or spaced-out interludes, then the members of Dark Funeral are happy (though they surely wouldn't use that word — it's practically taboo) to oblige.
Batman would make great literary fiction -- all that dark and broody introspection… with punching!
There was a strange positivity underneath all that dark subject matter — the scenes were tense but we had that funny exchange because we were actors who really wanted to learn from the other one, and every actor there.
All that crisp dark chocolate giving way to the creamy fondant – delicious.
Beneath all that, a dark-age set of attitudes expressed by a previously highly respected young British manager, which were associated by the LMA, after a day's consideration, with "banter".
Based on decades of indirect evidence, astronomers are all but certain that dark matter makes up the vast majority of all matter in the universe.
For some bureaucrats on the ground it's all that matters, the darker decision.
They are anxious about their children travelling – all that risk and the dark nights".
