Power fist schemes

[Dhx711]

Hey folks, it’s been a few years since I’ve touched the paintbrush, but I’m coming back in and starting to paint primaris marines as blood angels. 
 

When it comes to power fists I’ve seen several different schemes:  

- red casing with black fingers 

- black casing with red fingers 

- all red 

 

is there an official scheme that I should be looking at or is that all dependent on the unit?  

 

Like I know, they’re my marines, I can paint them any color that I want but I like staying chapter official for some things

[Cleon]

There's nothing current and official that I'm aware of, but GW painted Blood Angels terminators have almost exclusively had either all black or all black with hazard stripes on the back of the hand or chainfist blade.