Your violets look healthy..To me,only would they need some fertiliser..

they look like what we have here in louisiana. i call them a woodland violet but i am not sure if that is actually what it is. i think that the leaves should be a deeper green. are they getting a different amout of water than usual? sometimes too much or too little water turns leaves yellow. You may want to experiment and put one in a different area with a different amount of water.

Thanks for the advice ...
They are still a bit yellow but are growing...
Maybe too much water .. hmmmm
Merci & Thanks to both replies.
Pedro

I'm in north Texas, on alkaline clay soil. Your violets' leaves look like my violets' leaves when I don't fertilize them with iron chelate. The soil here binds iron so it is hard for some plants to absorb it. I don't have any iron chelate right now, so was going to try dilute azalia-rhodondendron fertilizer to see if that would change things enough for the violets to become healthy again.

Good luck and let us know how the violets, grow, please?