All this talk of turmeric and artificial food colouring to colour rice yellow!

Only one way to do it in my opinion - small pinch of ground saffron before the water goes in. Lovely colour, even nicer fragrance and taste.
And before anyone points out imperiously that BIR's don't use this, the only reason they don't is soley through cost factors. Saffron is simply too expensive for your average BIR to use.
And if you want a nice mottled varied white/yellow colour, simply soak some saffron strands in some warm milk for 10 mins or so and when the rice is resting simply sprinkle some in and let it soak in.
I actually cheat and use a small pinch of Paella seasoning in mine which is basically just ground saffron, ground cloves and ground paprika and salt.