They mean it's a milder-tasting mustard, with less heat, and it doesn't include vinegar, so it has a more balanced flavour, than for example a classic British mustard.
There's a reason mustard gas is banned. But no clear reason why Colman's isn't.
Sure there is - it's a substance that can't be easily vaporised, aerosolized, or otherwise distributed over a large area, and is consequently wholely ineffective as a large-scale weapon. Whereas mustard gas is only mostly (and sadistically) ineffective[0] as a large-scale weapon, and so makes it into the category of "war crimes that are worth specifically banning, since anyone would ever actually bother commiting them".
0: https://acoup.blog/2020/03/20/collections-why-dont-we-use-ch...
I once got the bright idea to challenge my friend who often irritated me with his imperviousness to what should be apocalyptic things. I proposed, in a state of misguided confidence, to do a shot of mustard oil. Mustard oil is a generally unknown ingredient in the green imposter most of us recognize as wasabi[1]. It's vicious. Anyway, he accepted the challenge, gulping the shot of mustard oil with a sweet grin of eagerly anticipated schadenfreude. I reluctantly took my own as pledged. The wretched agony that ensued! I writhed and squirmed in an almost hallucinatory pain until I was brought a bushel of fresh basil. Desperate, I chomped every leaf and stem and within minutes was well again, but have not forgotten.
Mustard can be dangerous. But I do love Colman's.
1. Most 'wasabi' isn't wasabi.
For these purposes, Dijon doesn't "cut the mustard" (sorry).
I've never liked English mustard paste as a condiment, nor that horrid dark brown stuff referred to as "French mustard", that has never been anywhere near France.
Watching Europeans (incl. Brits) watch Americans put mustard on things is always fun. The eyes go wide, and there's a look of panicked disbelief as you can see them thinking "No, stop, too much!!!"
Wasabi tastes like horseradish (both are roots), not mustard (a seed.)
A stupid story that probably explains more about me than I care to admit. I was making an egg sandwich one day and accidentally grabbed the horseradish sauce instead of mayonnaise, took a bit bite, and thought "hmm... that's funny, my mayonnaise must have gone off." this is where any sane person would stop and verify, but me, being me, went "better make sure" and took another bite. At which point I hunted down the container I used found out I had used horseradish sauce, decided it was actually pretty good and have been using it on my egg sandwiches ever sense.
They're from the same family though, and share the compound[1] that makes them hot.
Haha! It's true - a coke spoon looks just like a mustard spoon, but a bit smaller. Typically they're both silver (or plate).
Fresh horseradish sauce is something that most people haven't encountered; most horseradish sauce comes in jars from supermarkets, and is tame stuff. If you make your own from fresh horseradish, have a glass of cold water to hand. It's in a different part of the Scoville Scale.
I've had a few which were very mild, like Edmond Fallot, and one which was a bit stronger but still mild like Grey Poupon. Especially the Grey Poupon was perfect for this grilled ham I like to have in a sandwich.
Of course, now that I found a new favorite mustard, it's sold out due to the mentioned shortage on mustard seeds...
If you're using similar quantities as you would use for American/hot-dog mustard, you're just using too much of it. Use a small amount, spread thinly.