I've been wanting something for a long time. The ability to color wooden buildings. It would give us builders a lot to work with. I'm currently building a huge city and I really want an individual look to the houses.
So here's my idea for painting wooden walls and floors.
Artisan Table:
Paintbrush = 3 Fenris Hair + 1 Finewood
Upgrade = 2 Fenris Hair + 1 Finewood (Lasts longer between repairs)
1 Blue Paint = 4 blueberry + 1 Egg
(tempra paint is made with egg yolk. This would paint one panel of wall)
1 Red Paint = 1 bloodbag + 1 Egg
(And so on, following the same color recipes as banners)
It would only apply to walls and floors, not beams. When a painted panel is broken you would get the wood back but not the paint.
On the up side, lots of variation to what you can already build. On the down side, you'd have to wait until you were done with Yag or in creative mode.
Source: https://www.reddit.com/r/valheim/comments/1033ano/paintbrush_and_paint/