A clever colour trick when you’re aiming to create a cosy space is to combine two or three shades from one colour family.
For example, if you love blue, you could combine indigo, denim blue and violet – as seen in this beautiful bedroom. To create a similar paint effect as seen on the walls here, use loose brushstrokes to create the rough line effect and for the best effect, don't load the brush with too much paint.
Or if neutrals are more your style, why not pair a darker grey, such as pewter, with a soft dove grey and feathery white?