How to remain fairer even working in sun?

That's a very good question! I have a problem with sun exposure for medical reasons, and I do farm work. I highly recommend any sunscreen with an SPF of 100 or more that has zinc oxide in it. There are several out on the market. For your arms and other body areas, use the waterproof/sweatproof spray-on ones. For your face use a lightweight moisturizing version. And a very attractive floppy or brimmed hat (I wear a ventilated straw cowboy hat which is trendy and works well) will keep the sun off your face and neck.

There are lightweight clothes made that are also SPF rated, but I found that they were limited in the sizes available.