Given that you don't see critters, and I don't see the leaf webbing that spider mites can cause, I'd go with sunburn.

Some fuchsias are more sensitive to sun than others, but in general, I find they do best where they get morning sun and open shade from about noon on. I have grown them in western and southern exposures successfully, but they were in open shade, with the direct sun hitting them later in the day, say from 4 pm on. Your original placement probably was too intense.

Yours looks like a small-flowered single, and my experience is that these are closer to the wild types, and therefore a bit tougher.

If it is growing well otherwise, the burned leaves will soon be replaced, and the plant will carry on flowering. In the heat of summer and in a well-drained potting mix, watering every day is not too often.

I've had numerous plants go red from about May thru to winter 2013. Some were in my yard, garden, fruit trees but many more examples were found and photographed out in the fields. After 20 years in this rural, agricultural area this is a first. Trees are also dying and fall eventually. A large one fell in January and it's heartbreaking to me.

I'm convinced it is all being caused by the ongoing chemical materials used in Stratospheric Aerosol Geoengineering programs ( I recently read there are aproximately 60 of these programs currently in progress ) carried out by the government via the military. Primarily utilizing USAF aircraft and pilots. I don't yet know which chemical could be responsible for the reddish-pink leaves and spots. But they're appearing on all plants a little at a time. Even the grass that grows under water in the creeks.
Millions of people have become aware of this around the earth. This is called geoengineering and is a global endeavor. One document from the USAF is called "Weather as a force multiplier, Owning the weather in 2025" and outlines the purposes behind this huge plan. You can find it in pdf format online.

I've attached a link to my Facebook album of photos of the red leaf phenomenon. Also one chunk of firewood from an dead tree with red striations in the growth rings. FB Album called "SUMMER 2013, weird color plants." It's public but you may have to register on Face Book to browse there anyway. I don't know.

Here is a link that might be useful: SUMMER 2013, weird color plants