Do i need a undercoat?

[puddicat]

Thinking of painting my kitchen a light blue colour,the walls are a shade of mustard, will i need a undercoat before i start!!!

[heathfield]

Wouldn't do any harm. Use white - it's probably the cheapest colour and will definitely help the light blue topcoat. If the light blue isn't a dense colour paint, or you leave some thin areas, the mustard might tend to give the blue a greenish tinge.

[puddicat]

Thanks healthfield

[Tigerlilly]

Definitely, use a cheap white emulsion, it will mean that you should only have to do 2 coats of the (more expensive) coloured paint.