The truest colour in paint is Flat sheen paint, but in the past the most difficult to impossible to clean.
Well, selecting paint sheen just got easy when Benjamin Moore developed a product called Aura. Reason is that even the flat sheen is washable. Gone are the days where Flat paint is impossible to wash. Benjamin Moore Website says this,
“Our groundbreaking Colour Lock system protects paint colours from fading and rubbing off—even after repeated washings.
Developed for premium-quality Aura® interior and exterior paint, our Colour Lock system is formulated with proprietary waterborne resins and colorants that lock in colour particles tightly throughout the paint—not just on the surface, like many paints on the market.” – http://www.benjaminmoore.ca/en-ca/for-your-home/colour-lock-fade-and-stain-resistant-paint
Candice talk about this in this short video.