The Nexus 5 has a known issue with its display. Affecting all models from the first manufacturing run and most models thereafter, this display issue is easiest to notice on something with a white background. A yellowish tint, most noticeable when compared to other devices, seems to emanate from the Nexus 5's screen.
Thankfully, there's a fix for this issue. It's not an official one from Google, but it gets the job done quite well nonetheless. A combination of works done by developer Francisco Franco allows us to correct the screen—one a kernel, and the other a display calibrating app.