Yes, only occasional coffee drinkers have problems with sleep caused by caffeine.
just like when you smoke, after few days of stop the first cigarette gets you drunk : )
Also a little word about dilution in another meaning, the 'color' of coffee or tea is not related to caffeine. Caffeine is very soluble in water and has no color.
Some think that Italian coffee (expresso ristretto) is very bad, being too strong and too rich, and think that they will never sleep. Then they have long coffees instead (Lungo, or French coffee)... But, in contrary, a ristretto is very poor in caffeine and a coffee almost as transparent as a tea can contain all the grain's caffeine.
For tea, caffeine gets in water very early when you prepare it. More you let tea infusing, more you'll have tannin that make it bitter, and tannin attenuate caffeine effects.
(I don't touch any 'energy drinks', so let's assume that what is written on the box concerning caffeine % is real ^^)
So I think what you are saying, is that what we call dark roast here in the US, is actually less caffeine than a light roast or breakfast blend (that's what they call it in the US). I learned that a few years ago. I always assumed that dark roast had more caffeine, but it does not.
Caffeine has a half life too, and I am notorious for drinking it later in the day. My liver needs time to clear it properly, so it won't mess up sleep. I still fall asleep fine, but then I wake up 4 or 5 hours later, tired, but unable to sleep longer (I usually sleep a full 8-10 every night, or I am grumpy AF the next day). So for me, it has a lot to do with the half life, as well as the time of day I am drinking it. Days I drink more, I drink morning and afternoon. Days I drink less, I drink morning only. So that plays a role, as well as overall amount. Haha Science nerd alert.
What
@ForceTen said is a good reminder for me. I am trying to drink more green teas, because it has l-theanine in it, and gives a less jittery buzz. I just can't stomach it without meals, or it makes me nauseous, so it's not as easy for me to grab as coffee. It is a lot healthier, in so many ways, according to my research though. I wish I was one of those people who could drink green tea on an empty or low food stomach, but I will start vomiting, so I gotta do a full meal with each cup. I am always "about to start drinking green tea tomorrow". Tomorrow just never quite comes.
Yeah, when I said the solution dilution thing, I meant chasers of water after the fact. Not dilution in the cup. Like if you consume too mach of a psychoactive drug or alcohol, it's good to drink a lot of water, to assist your body in clearing it faster. I think that's how it works anyways. I know when I drink alcohol, especially in large amounts, it's good to drink as much water before bed, and leave some by the bed, if possible. Helps w the next day. As well as B vitamins, and leaving some tylenol by the bed too
The science of preempting a hangover, lol. I spent from age 20 to age 30 working on that one