I am looking for a nice turquoise colour to paint my cottage walls.

You can have a paint color mixed to your specification at any hardware store that carries paint.

Check with your local hardware stores that sell paint. Most can mix paint colors to your specification.

It will be in your best interest to get paint charts as a start.

I would get color swatches from the paint department and hold them up, then if you narrow it down, you can even get small samples of a few, swipe some on your wall and stand back and see which one you like best.

For a light color, consider Sherwin Williams "Sea Salt." For a medium shade, Benjamin Moore's "Wythe Blue" is gorgeous. For a really bright color, try Benjamin Moore's "Florida Keys Blue."

Get various paint samples from a paint store tape them to your wall. Then move them to another wall as the different lighting will change the color.

I find that you can get a subtle color by choosing a color you like however intense and have them mix a gallon with colorant for a quart or pint. Doing I this way means that you can get more if you need it.

That will look amazing for your cottage and here's a few ideas. I think a entry way wall will look great then into the next room a full color.

I've only used it on a front door, not on an entire room. Stratton blue is a great color, just a little deeper and darker than Wythe blue. With your light cabinets, ceiling and trim, I'll bet your room could pull it off beautifully!