What soft furnishings do you have. You could pic out one or two colours as an accent colour and use that as your Base for the curtains. I currently have cream hessian walls and have a duck egg blue and chocolate curtains. I'm currently making matching Oxford cushion covers for the settees . If you can't find what your looking for ready made buy the fabric and have bespoke curtains made for you.

Consider Grey or white. U could also use geometric or any pattern in mint green

In civil engineering this condition is known as efflorescence this condition occurs due to capillary action of water in brick in which water contains diffrent salts comes on surface through voids of brick and evaporates and salt rest on surface as shown in image this salts may be harmful or not this depends on type and chemistry of salts generally it is not harmful

Teal is a very trendy colour, but having it on all four walls may be an overkill in the kitchen, especially with that dramatic chevron dado tile. I hope at least the 4th wall is white! The cabinets have to be white too