Primer for walls with existing colours

[sweetpickle2]

Posted this on another board but hoping to get more answers here.

Have recently moved into a house with two colours on the bedroom walls- dark blue on the ceiling/halfway down, and white underneath.

Its not my style so I want to repaint, but will I have to prime so that the colour going on is even, or will it not matter?

Primer is the type of paint you need for bare wood. I think you mean undercoat? Yes you will need to undercoat. I would give it a couple of coats of white before you put anything else on otherwise the blue will show through. Probably worth buying branded paint as it will cover better. Something like Dulux professional white should do the job.

Thank you- yes I guess I do mean undercoat! I am completely clueless about this, have only ever painted a magnolia room a slightly different shade of beige before.

Homebase do a basecoat.

If the wall’s in good and smooth condition , just a trade white or magnolia is fine.

We have just covered a dark grey and did 3 good coats of trade white to cover it

A good quality white paint will do the job if you want to lighten the colour on the blue wall. No need to worry about the final colour being even, it’s more an issue of how many coats. As white paint is cheaper we did one white and two of the final off white colour, mostly over grey and cream when painting a light off white. You may need two coats of white on the dark wall.

Higher quality white paint will have better coverage eg Dulux super matt in our case. We’ve almost used five 10 litre buckets of the stuff over 2ish years.