You're most welcome aethereon, I am glad it was helpful and it puts a big smile on my face too!

yes you're right, the color change is not as clear in the initial stages of the extraction. in the first basification step after the harmalas had settled the solution on top remains brown, at later stages the color will be yellow, and finally when the haramalas are clean the water above them should be colorless.

the idea of using sodium carbonate and few drops of NaOH solution is meant for the very final basification step if you're desired end product is the freebase. at that stage the harmalas should be quite clean and the color change is easier to observe. so if your harmalas are dissolved in an acidic solution the color should be a good yellow/orange. If you basify with sodium carbonate only, the PH will not be high enough to fully convert everything, some harmalas will remain in solution and give it a yellow tinge, the amount is negligeable but I like to add few drops of NaOH solution to fully eliminate the yellow color. when you add the NaOH drop by drop and observe closely you will not see harmalas crashing out anymore but you will see the color change where the drop hits, you then mix a bit and add another drop and observe, repeat until the color stops changing. it can still be a bit yellow because of impurities so you should rely more on the color change.

I added a photo showing the water nearly colorless in the final basification step and after a couple water washes

have you seen the holy mountain? I love all the films by Alejandro Jodorowsky.