Add the oil and annatto seeds into a small pot.
Heat the oil on low until it comes to a boil. Allow it to simmer for 5 minutes, or until it achieves the desired color.
Do not heat for more than 10 minutes to avoid the burning of the seeds.
Allow to cool and strain the oil into a glass jar.
If desired, you can save the annatto seeds for another time as you can use the same seeds twice.