I bought a house!

[Niwashi]

Open the housing menu while on your estate and it will display several options. One of them is dyeing furniture^^
It gives you a list of all placed furniture, either greyed out (non-dyeable) or normal, in which case right-click it and select the dye (looks the same as the window for gear dyes).

While the window looks like the one for gear dyes, the dye itself quite often does not. The pieces I've tried to dye all combined the dye with the default color, giving far more weight to the default color. So if something starts out brown, you might not be able to make it red or green or blue, just brown with a faintly reddish cast, or brown with a faintly greenish cast, or brown with a faintly bluish cast, or whatever. (I found it rather disappointing, but maybe you'll have better luck with the pieces you want to color.)

[ErikMynhier]

We have a 4* crafter in our FC. She makes everything for the FC and the personal.