Almost certain it comes down to the age of the vine and climate levels. Such as 'Peruvian Red', 'Ourinhos White', or 'Cielo Yellow'. As this is merely just speculation but climate seems to take its toll very specifically. The white and yellow vine may certainly may be cultivated in the very same region but it has been confused with the title 'Ourinhos'(little gold). It has been going through SWIM's mind too of the alkaloid content through the strains, but would expect fluctuations of harmalas(harmaline/THH).. However, these matured vines grow very THICK and wonderfully intertwined. Flowering ever rarely, these vines are most cultivated for potency.
If you're looking to experience the vine in its true form, white would suit you.
In the end we will conserve only what we love. We will love only what we understand. We will understand only what we are taught. ~Baba Dioum