I shoot with a Nikon D3400 and I am a beginner casual photographer. I shoot in maximum quality jpeg(NOT RAW) on auto white balance. Recently my friend and I were shooting some same subjects(my friend also shoots on jpeg auto white balance) and I noticed that Canons white color was more white and overall picture seemed more white compared to my Nikon. My Nikon has a very slight yellow cast to every image when compared to Canon. I thought it was my cameras problem but later when I checked jpegs of Canon and Nikon from the internet I saw the same thing. All Nikon jpegs seem to have a slight yellow cast when compared to Canon jpegs. Note- These are not raw to raw comparisons but jpeg to jpeg comparisons.
When you shoot straight to JPEG and use "Auto White Balance" you are at the mercy of an automated routine and the firmware behind it that was created by a software engineer. If you want greater control of color in your photos you need to either manually set the color temperature (blue←→amber axis) and white balance correction (fine adjustment along both the blue←→amber and green←→magenta axes) yourself, use lighting with carefully controlled color output (such as studio strobes), or shoot in raw and carefully adjust the color in post processing. Taking calibration shots of calibrated color targets under the lighting you will be using is also very helpful if the lighting is fairly consistent and does not suffer from the effects of flicker caused by alternating current that changes the color output from one shot to the next.
In general, Nikon's default color profiles tend to emphasize blues and greens (green is a combination of yellow and blue) in a way that works well for many types of landscape photos. Canon's color profiles tend to be set to render pleasing skin tones. This tends to hold true if the lighting used is more or less full spectrum.
Under certain types of limited spectrum lighting (light that does not contain a full spectrum of wavelengths when compared to sunlight or light from other black body radiators), the way a camera will render color using "Auto White Balance" can vary significantly based on the way the camera has been programmed to respond to such lighting. In such a case, you're at the mercy of the camera's programming.