The peculiarity is this…
Traditionally Chinese Paintings did NOT have a coloured background. Rather the hue of paper would allow some degree of mood swing on content painted.
The westerner always paints in the details of what was in the background of the painting, a church, some trees, a blue sky and some clouds but the traditionalist doesn’t add these elements
Some of the beauty of real traditional Chinese art is that it isolates the subject without a background no matter what the background.
Otherwise the question is a complicated one.
To colour the background depends on the type, thickness, age, resistance to water, fibre type and size of the paper used and then the colour required, its paint substance, the viscosity, the acidity of the water, the density of the mixture and on and on and on.
In art there is no recipe that’s universal.
You experiment as we all do.
And even then, this week it looks one way next week another because weather changes, humidity changes, speed of drying, and so on.
The PERFECT way? you nee an airbrush and paint solution that will work through it. This way the mist is so fine it will discolour the paper without droplets and without tide-line.
Be confident. Anything goes. This is art. Not cake baking. 🙂