Painting wall for screen use in daylight

I'm looking for a paint mix (I'm in the UK), that will work well at night but also well in daylight with blinds up. A white wall isn't cutting it.

What mix should I be looking at?

I got a pot of this paint - Wickes Colour Home Vinyl Matt Emulsion Paint - to test and I've found when compared to the white wall (I only did a small test square), whites look all wrong, they look grey rather than white but I'm unsure whether this is the paint being too dark or is it a perception problem?

Many thanks.