2. It's not dishonest as floating labels typically are designed a certain way — with tiny text labels and crammed spacing. This is the standard for how they're designed. Can you make it bigger and give it more spacing? Yes, you can go out of your way to do that but most typically don't because of the way floating labels are designed — the label is center-aligned in the field from the start and then it shrinks and floats to the top because it's not thought of as important anymore. This is standard behavior for floating labels. To suggest, "oh, you can just make it bigger then and put more spacing" shows you don't understand how floating labels typically work.
3. You ignore the fact of how many normal-visioned users the color label differentiation would help, which is a lot since they make up the majority on most apps. Your complaint on accessibility doesn't really stand since it can be resolved by making the label color a higher contrast and greater luminance for disabled users. Many users want to check their fields before they press the submit button and get errors. The label differentiation makes it easier for them to spot incomplete fields. These are great things for the user.