Grey or yellow black out blinds?

[wingingitalltheway]

We are planning to buy some black out blinds for our bedroom. Currently have blinds that let so much light in.
Our bedroom is grey and yellow but can’t decide which colour the blinds should be!
Originally I thought grey would be better as this will make it even darker but would this make the room too hot on a morning when the sun rises?
Any thoughts?

I'd go for black if you want to completely black it out - during the day roll it up to the top so you can't see it.

The level of blackout is NOT dependant on the colour of the blinds, if they are "total blackout". Chinks of light around blinds are what affects the extent of blackout.
For total blackout in a bedroom I would suggest blackout roller blinds plus blackout curtains with a box pelmet for the curtains.