First I heard of wanting to have a yellow plant at harvest. Green = health as far as I know. It is true that you do not want high Nitrogen levels during flowring, but most fertilizer companies give you the regimen for the different cycles. Yellowing means problems with nutrients in "Indoor Grower's Bible", which also suggests to do the copius flushing with just water in just the last week or so of growth. Most plants have roughly a 60-75 day flower cycle and you need everyone of them plus optimum fert program for them to have energy to Grow Big! That taste could be leftover ferts if not enough flush, but hard to say since you flushed over an extended period.

I love to read the books and mags on maximizing growth. They are an investment with big returns. Good luck!