The best colour for roller blinds depends on several factors such as your room's overall aesthetic, the function and ambience of the room, the existing décor, the colour scheme and of course personal choice.
Generally, neutral tones such as white, black, beige, cream or grey are versatile choices that work well in most spaces. They won't clash with existing colours and give you flexibility for décor changes in the future. Light colours can open up a room, whilst dark colours create a cosier atmosphere. Warm colours energise a space, and cool colours evoke calmness.
Personal preference plays a big role, so you'll want to choose a colour that resonates with your style and enhances your space.