Long but sort of funny explanation of this image:

One thing I wanted to do when we returned to Casa Batlló was to get a more head-on perspective of this wonderful fireplace in order to show the mushroom shape of the enclosure. When we arrived at the fireplace it was free of tourists for a change, but there was a photographer with a camera and tripod set up exactly where I wanted to be, to take pictures of visitors that they could later purchase. Naturally, she wouldn't move her gear, so I made do from a bit off center.

However, when I was processing this image, I looked at a photo of the fireplace in a reference book, and it was BLUE! I simply couldn't believe it, so started researching the "actual" color -- and found every possible variation from yellow to red to blue to greenish. The official Casa Batlló website shows it as red in one image and gold in another (!), but an excellent quality Gaudí book I have shows it more as red/black with the exterior wall more on the yellowish side. So this was what I came up with -- the truth is, I don't really know what color the fireplace and wall are after all of this -- but I guess everybody presents it the way they remember it.