Is this a metaphor or simile when Pip first describes the marshes in Great Expectations by Charles Dickens and the sky was just a row of long angry red lines and dense black lines intermixed?

a metaphor is a figure of speech in which you use different visualizations to portray what is really going on.

for example:

3 men are cornering their enemy.

"So, the rabbit has been hunted down by the wolves" one of them says.

of course, they are not wolves and the other guy isn't a rabbit, but these themes help to portray the helplessness of the enemy guy and the likeness of the 3 guys to predators closing in on prey.