Could be an old sample. Dye lots change. From a paicture posted on a computer monitor it does not look bad but the picture could be way off.

Yes, the materials that go into the product get discontinued/changed, so the end product can vary a bit between dye lots and definitely for old samples.

The way to try to reduce the risk of this happening is to ask the fabricator, showroom or manufacturer to send you a sample that is from the current dye lot or production batch.

Totally common--happens all the time. Could be an old sample that has oxidized or otherwise changed color over time. or a new lot that is different from the sample.

The only way to know what you're getting is to contact the fabricator or stone yard and select the actual slab. Then have it marked with your name and contact info.

Who provided the sample to you? If it was your fabricator/designer, a recent sample should have been provided to you (they would both be aware that the slabs can change colors depending upon the lot). I wouldn't be happy about the change in the white background color - I assume that it probably is causing an issue with the other materials that you've selected?