What happen?

I’m thinking mostly of over-growth because it’s been pale for only a few days. Thank you for your answers.

If your soil ph is in range, it looks like light nitrogen deficiency or those leaves are not exposed to enough light. On very bottom they will naturally defoliate. I would double check your levels and if you are not flowering yet it needs a little more nitrogen. If the paleness is just In those bottom leaves I would not get super stressed. Good luck and happy growing 🌱🌱🌱

Your plant looks overwatered or like it has nutrient lock out. It shouldn't be that pale of a green. That's what plants do normally if they get over watered and flooded. But a plant will also do this if it has nutrient lock out. Have you checked your pH? Is your soil really wet? How long has the plant been fading?