I've noticed with Nova that colour does not always reflect extraction. I often get a mesmerising, thick, potent hit that rocks me. I look in the herb chamber, and most is brown, some yellow. Not uniform. However second hits don't give much at all. I've even tried extracting the AVB in other vapes and it doesn't seem worthwhile.
So I've started using the potency, and thickness of the hit as a determinant for considering extraction level over appearance.
Anyone else with similar experience? It should be noted I only half fill the chamber at max, and go for a huge rip.