Grammatically, when we construct a first conditional sentence, the if-clause is followed by a result clause with a "will" in it. However, in many formal texts written by native English speakers, I see that the result clause contains would instead of will. I have been searching for a grammar lesson explaining this for more than a year but of no avail. Could you please help me understand what is going on in such a structure? Here is an example from one of my textbooks:
If we continue in this fashion, letting the paint colors get progressively lighter with each successive choice experiment, she may express indifference at each step. Yet, if we offer her a choice between the darkest shade of gray and the final (almost white) color, she would be able to distinguish between the colors and is likely to prefer one of them.