How do the rice in Thai pineapple rice turn yellow ?

I've searched a few recipes but I don't see how the ingredients can help the rice to turn yellow in what I see in most restaurants. So how on earth do I make them turn yellow ? What's the best recipe around to create authentic Thai pineapple rice?How do the rice in Thai pineapple rice turn yellow ?
A 1/4 teaspoon or so of turmeric will turn the rice yellow, and is much less expensive than saffron, which of course also turns it yellow.
I believe that most of the rice you see in restaurants that is yellow is that way because of 2 possible other ingredients:

One might be Annatto, a spice that gives a yellow or orange-like tint to food and adds a touch of peppery/nutmeg flavor to it. You can easily buy Annato in the grocery store. It's either in the spice aisle or in the Spanish or Latino section.





The other thing that it might be is saffron. Saffron is the most expensive spice in the world but many grocery stores have it for sale. You only need to use a tiny bit. Many Indian restaurants use it to flavor their Basmati rice. It's hard to describe the flavor from saffron but it is very good.How do the rice in Thai pineapple rice turn yellow ?
The recipes that the restaurants use probably call for saffron.
Others have already mentioned saffron. A cheaper option would be turmeric.How do the rice in Thai pineapple rice turn yellow ?
Yellow curry, duh.