Note that "blood relationship" is step-by-step, not end-to-end.
So you can go from yourself to a cousin of a cousin without changing colour, although you share no blood with the cousin of a cousin.
(This only happens if the parents of the cousin in the middle are unmarried. Otherwise, the chain skips the cousin in the middle and goes from one parent to the other, changing colour).
A more common case is
yourself -> half-sib -> stepparent
Two blood connections, so no change of colour, although you share no blood with the stepparent.
if you don't have a half-sib, the chain goes
yourself -> parent -> stepparent
and changes colour.
Likewise if you have a step-sib, the chain will go through a common half-sib if you have one.
The math textbooks will say that blood-relationship isn't transitive.