The Picture Style editor is not for editing pictures. It is for creating and editing Picture Styles, which is one of the settings you can use when taking photos. With it you can alter the tonality, sharpness, contrast, and saturation of your photos as you take the photo. That way, you don't have to do as much editing of the photo on your computer. This saves time. For example, if you're taking a bunch of portraits, you're going to want to have the camera capture the image so that it is less harsh and skin tones are warm. Or, if you're taking a landscape photo, you might want the greens and blues to be more saturated. On the T6i there's actually a specific button for selecting the Picture Style, and it's right below the Set button. Press this and you can select any of a half dozen or so preset styles. Or you can use the camera menus to edit your own. Some photographers don't bother with Picture Styles, but many like the creativity of the Picture Styles function. More on reddit.com

To bad there isn't more of a general Canon forum. This isn't really a lens question. New discovery (for me). I downloaded Canon's picture style editor. It's a new concept to me. I'm familiar with in camera picture styles. Auto Portrait Landscape Fine Detail etc. As I'm sure most of you... More on dpreview.com

Adobe Lightroom. It's more than an editor though, as it's also a photo catalog program. More on reddit.com

In the Canon world, picture styles are the counterpart to Fujifilm's film simulations. One can transfer up to three picture styles from your computer to the camera with the EOS utility or use arbitrary many in Digital Photo Professional. If you want to experiment yourself, it is possible to create picture styles with the Picture Style Editor. However, there are also quite old picture styles available for download from Canon . I assume that these are save to use. Thus, it would be possible to share something like film recipes for Canon cameras. Unfortunately, this has never become very popular, although there is even a Flickr group . There is a posting about 154 picture styles containing a link to a page offering a download of these styles, which still works after so many years. However, nothing in the world could make me transfer one of these very old picture styles from unknown sources and unknown quality to my camera! Using some of them in Digital Photo Professional is by far the better choice in my opinion! And I would try them out in the Picture Style Editor beforehand and resave the presets I want to use. More on reddit.com