Yes, you're right about the colors being so confusing and the same problem exists with daylilies and many other plants.
Lighting, natural or artificial, monitors, and cameras can all add to the confusion. Thanks for the compliment about photos. Three years ago I bought a new Fuji camera, thinking the light weight and smaller size would be great. Little did I know the depth of color (for better or worse per a person's perspective) was too far off to be believable. Here's an example with each photo taken by a Fuji (old and new). I returned the new one the next day.
As for the true color - here's the page from Blooming Bulb, where I purchased it: (this may be a stock photo, which doesn't mean it's honest)
http://www.bloomingbulb.com/p-...
Here's photos by bsharf who has many amaryllises:
It's some shade of dark coral to salmon. I know that's not helpful but the best I can offer! It's the actual look of the plant that I like - the soft color, rounded edges on the petals, etc.