How to change default colours of the code block provides?

The code block formatting is fine it was added as (without the “”)

"``` swift

[code here]
"```

It highlights as follows, but the issue is the colour it provides, I don’t like it. It gets highlighted as below. (see the red colour “jjj”, I want to have it in blue colour.

But I want something like the following

Is it possible to edit a file etc via terminal? so I can change the default colours assigned for a specific language?