I have seldom found a problem. If I wear reading glasses (purchased PURELY for reading fine text on an iPhone screen) my vision is better than normal. On any occasion when I find text colours that are difficult to read, I kill the website. If they haven’t a clue regarding readability then I feel that anything else they offer is also likely to be suspect. Sometimes if I have further phone, text, or face to face contact I will mention that their website succeeded in annoying me. That is usually met with an apology and promise to look into the matter. Some web creatives have no concept regarding what they are supposed to be creating. They regard “different” as an achievement.