„no carbohydrate intake at all for half a day before“ no way your body was in ketosis.
It may be that you disagree, but I get the feeling that you ignored the "doing keto" part of my setup, and instead thought that the person in question was eating cake 12.5 hours before the workout. :)
The depth of color indicates how concentrated ketones are in your urine, which is impacted by (1) the amount of ketones your body is producing, and, very importantly, (2) your hydration level (i.e. how diluted your urine is).
For newbies, if the stick is pink AT ALL, congrats, you're in ketosis. Don't make the depth of color a big goal.