Now I know why it's called the "Blue" house. I always hear about it in Korean dramas and series. It looks magnificent! I was supposed to visit Korea last July but my trip got cancelled due to the pandemic. I will definitely be adding this to my itinerary.
A lot of the dramas either just refer to it or show the inside. They also call it by the Korean name, Cheongwadae and Blue House is just its English name.
I recommend you visit on the same day you do a Gyeongbokgung Palace tour since the bus leaves from there anyway. Just make sure you reserve in advance. Luckily there are spots available for foreigners which are much easier to get.