Here in the United States, an ESA is a separate classification, distinct from a Service Animal or pet. You go to your psychiatrist with a mental or emotional problem, such as PTSD, and one of the things they may do is give you ESA documentation. Essentially, they prescribe you a cat or whatever.
ESAs usually are not restricted by species or breed, nor do they require any specific training, but the ADA (Americans with Disabilities Act) doesn't have the same protections for them as for Service Animals. Businesses do not have to allow them access, for example, no matter how loudly Karen shouts. In practice, though, business owners really don't want to fuck with the ADA, so they'd rather let fake ESAs in than risk getting in trouble over a proper Service Animal.
It's really a pale blue. If it were white, the visible spectrum would be pretty even, but you can see the graph is higher on the blue edge and lower on the red edge. There's enough green and red to brighten it a lot, but it's definitely blue.
In fact, the sun's surface temperature is around 5800K, and you can look up what color that actually is wherever you go light bulb shopping.
This shows the colors based on temperature, and the sun is firmly in the "Day White." It's called white, but you can see it's pretty clearly blue, especially next to the "Direct Sun" color.