I grew up in India and now live in the US. My mom recently got some ground turmeric from our own farm when she visited us. I am was stunned by how much more duller, brownish-yellow it was compared to the turmeric I buy in Indian stores in the US. Those are usually really bright yellows. Now, I am really scared that even stuff sold in California is probably lead paint tainted turmeric.
The difference could be due to sun-drying (I assume?) on your family's farm vs. industrial scale freeze/spray drying, for example. Or some (non-lead, non-colouring) additive that prevents it oxidising and dulling over time perhaps. I think argon is often used (rather than air) in packaging for that purpose.