(When I doubt that my info is not certain, I search to confirm)
The info below explains why all salts will taste ALMOST identical in water because they are 97% NaCl. (I initially said 99%)
Food grade salt quality must meet the codex alimentarius to be approved for food use, sale and processing (in US and Canada at least)
This standard applies to salt used as an ingredient of food, both for direct sale to the consumer and for food
manufacture. It applies also to salt used as a carrier of food additives and/or nutrients. Subject to the
provisions of this standard more specific requirements for special needs may be applied. It does not apply to
salt from origins other than those mentioned in Section 2, notably the salt which is a by-product of chemical
Food grade salt is a crystalline product consisting predominantly of sodium chloride. It is obtained from the
sea, from underground rock salt deposits or from natural brine.
3. ESSENTIAL COMPOSITION AND QUALITY FACTORS
3.1 MINIMUM NACL CONTENT
The content of NaCl shall not be less than 97% on a dry matter basis, exclusive of additives.
Of course there are various <salts> in the ocean but crystals form from pure salts. Since crystallization is unique to each salt,in chemistry, it is a method of purification. NaCl will form crystalline salt that is pure when sea water will evaporate. All other salts will stay dissolved. Salt ponds are never left to dry completely.
Complete drying of seas results in a product called Natron (many salts including NaCl) found around the world but particularly in ancient dried lakes in Egypt. Natron was used to dehydrate bodies (for months) before mummification. Almost like salting fish to preserve them.
I seriously believe that gourmet colored sea salt are intentionally mixed with clay or other matter in the pond to make it appear very exclusive and unique.