Branding

I also found it a bit difficult to follow along with the branding of Spotify. So I will try and help to layout out some solid ground work to get you started.

Color

Green

Pantone 376 ¹
HEX = #81b71a
RGB = 129,183,26

Light Set ³

White: #ffffff
Black: #000000
Grey: #999999
Lt. Grey: #e6e6e6
Blue: #0993c7
Green: #82b919
Blue-Green: #19b9b7

Dark Set ³

Black: #000000
Dark Grey: #262626
Grey: #999999
White: #ffffff
Orange: #ff6000
Red: #f25555
Yellow: #ebd411

Typography

The Spotify logo is a custom font called "Spotify Lagom Bold and it’s a tweaked version of the typeface Akkurat" ²

They also use a hand sketch font that is custom and it sort of looks like Sketch Block. The same font I used in the title.

You can find other fonts on their UI Guidelines page.

Sources

¹ Rasmus Andersson was the "head of everything-design" at Spotify and he wrote a pretty good article on GitHub where he talks about branding. I don't now how accurate this is, but it was updated 2 months ago.
² Kribba who is "Head of Design at Spotify" (according to the little bio) answered Does anyone know the name of the font used in Spotify's site?.
³ I grabbed the colors from the image in UX Guidelines - Colors