Agave eggersiana growing outside in Missouri, USA. When night time temps are below 60f/15c I take it inside. Last year while outside it turned this light green that I don't think seems very healthy and I was hoping it'd improve this summer but it hasn't. Maybe I need to add nitrogen to the soil? Pot drains well.
I would do a bit of research, figure out a fertilizer regimen for it and see if that doesn't green it up. Increased light with no increase of nutrients will sometimes cause them to yellow like that. You can get soil tests at most hardware/lawn and garden stores. You might grab one to go with the fertilizer so you can keep an eye on it and don't burn it.