I have a project consisting of a video and some partially transparent images, which are screenshots from that video edited in Gimp and made transparent everywhere but the places I edited.
There's the usual issue with colorspaces, that is, when images are imported into timeline with Composite transition, their colors become dull as in http://www.kdenlive.org/forum/problem-video-colors. In my particular case, "Full luma range" option on images does nothing. When this option is applied to the video, it similarly distorts video colors, so that colors between images and video (almost) match.
For some reason, when "Full luma range" is unset in video and the image is applied with "Affine" transition instead of "Composite", colors match. This way, everything looks perfect in project monitor. When rendered, however, colors within frame where the image is applied match perfectly, but they are still distorted, so there is a noticeable color mismatch between frames where image is applied and where the oiginal video is unchanged. I tried H.264 and MPEG-4 profiles.
Am I overlooking something, or is it a bug?