Kolsch is supposed to be clear, crisp, and clean flavored, so its not something that is commonly flavored.
Which, in my book, means its a really good idea to try it.
To make it "Spring-like".... I'm thinking herbs, rosemary or thyme. Or maybe citrusy with orange, lemon or lime zest.
On brewing hiatus until back problem resolved.
Drinking: Banana - Lavender Honey Melomel, Cherry Schwarzbock, Cranberry-Welches Wine, Hazelnut Sweet Stout, Moteuka Amber Ale, Three Goats Gruff Cyser, Smoked 70 Shilling Bottle Bombs.
Brewing/Drinking blog: http://beermonday.blogspot.com