There are multiple reasons why you will have different levels of krausen in different beers. As @Frank van Wensveen pointed out, melanoidins are one source. These are produced by Maillard reactions during the malt kilning process (i.e. making dark malts) as well as during any similar heating process, such as a decoction mash (where a portion of the mash is removed and boiled in a step-mash process).
Other sources of high krausen include: using ale yeasts instead of lager yeasts (clearly a bottom fermenting yeast will produce less krausen than a top fermenting yeast), hop oils, proteins, vigorous yeast, and wort density, to name a few.
The mere fact that a beer has dark malt is not determinative of krausen level. By way of example, measure the krausen height of a dark ale you brew. Then make a simple blonde ale using K-97 kolsch yeast (a yeast with a notoriously thick, persistent krausen) and measure which is taller. Alternatively, you can view pictures of K-97 krausen for comparison here (or on any similar forum via a simple internet search): https://www.homebrewtalk.com/threads/safale-k-97-questions.586790/
At the end of the day, the amount of krausen is due to many factors, not simply malt lovibond.