The water makes a hole in the stone not by violence, but by oft-falling Lucretius
Here’s another deceptively simple exercise for you.
Do this once or twice, and you might be intrigued by how off your guess at a value is, especially for higher chroma colours.
Do it repeatedly, do it every day, and you’ll build your value-judging muscle like a weight lifter lifting weights.
I’ll email you a link to the third exercise in another week.