Selections must be done live and in person. Natural stone is highly variable. No 2 slabs are identical.
Quartz samples will have true color tones, and brochure photo’s showing the veining patterns can be sufficient to comprehend the effect of a full slab pattern. Seeing a full slab of quartz is not essential but can help validate the selection in some circumstances.
With technology tools and jam packed schedules, it’s very tempting to select natural stone, or quartz material electronically. For going travel and time to stone supply warehouse is. This is a very bad idea. While digital photography will do a wonderful job illustrating patterns, flow and veining, used widely as part of vain match tools. Colors are a complete wild card. True color may be captured and transmitted OK, but the issue is on the receiving end. Every display will have settings that can be adjusted period from PC monitors to phones and Tablets there is no true color standard, so results are almost never true. When investing thousands of dollars into a counter you will have to live with for many years, there really is no substitute or shortcut.