Both are perfect but Blue is my favorite for sure. I've only watched White once and my reaction back then was that it was good but not up to par with the other two but I plan on rewatching it soon though.
My main problem with Red is that it has too much dialogue, I prefer Kieslowski when he's showing instead of telling. I also think the main theme in Blue is more interesting. It comes down to personal preference as they're all really well made of course.

Peeping Tom (1960)

Pretty good horror/thriller, with a well constructed and unsettling psycho. The movie doesn't try to surprise or create suspicions as the viewer knows what's going on from the beginning, but yet it manages to create a good sense of uneasiness in almost every scene.

Jail Bait (1954)

Yeah it's bad, it has some funny parts but they are few and far between. Not worth watching in my opinion.

Suicide Squad (2016)

Cool characters, pretty good soundtrack - meh movie.

I liked White for his different tone. I even would go as far and call it a comedy. Hard to say which one is my favorite though. As you mentioned Blue has a great theme but I also like the developement of the relationship between the main protagonists in Red.

Yeah I'd also call it a comedy, I'm favouring darker I usually favour straigh Drama over drama / comedies so that's probably why I like the other ones better. Have you seen the Dekalog? Episode 10 is pretty similar to White in style so Kieslowski is definitely no stranger to working in the comedy genre.

The Guard (2011)

fucking hilarious, haven't laughed this hard since The Grand Budapest Hotel

No I haven't seen anything from him besides the colour trilogy.

Big - charming
Me and Earl and the Dying Girl - realy good, I liked it
Jack Reacher - not my cup of tea
Army of One - Okish ... Cage is perfect in his role.

All right. Dekalog is a massive project to take on of coure so it's understandable if you don't want to rush it or whatever but at the very least check out Double life of Veronique if you like Blue / Red, they are very similar