I wouldn't worry about the color of the bulb bomb, but thinning towards the root is not good I reckon. It is better to thin upwards toward the tip -- shows your hair is thickening up. But I'm not a hair specialist ...
How long have you been on finasteride? Could be finasteride's way of showing you, it's doing something ... I remember when I first when on finasteride. 3 years ago, I shed a ton of hair (and I mean fill-up-the-sink). A lot of them were vellus but a lot of them were terminals and anagens too.
Right now I'm shedding like crazy too and I have no idea why. The hairs that are thinning are thinnest at the tip and thicker at the root. I don't know what's going on. I just buzzed my head just to say, "f*** it."
D.