Oh, I'm home, so I can explain it.
The court colour is edited with Hex Editors. We'll edit xxcrt.o for this job.
You should find ******FF, which is repeating multiple times.
For ******, let's pick 004c30 as the colour we want to put on the court and bac3c8 as the actual colour of court.
It'll write C8C3BAFF and it'll be repeating.
Have you noticed that BA and C8 switched? Yes, the first 2 characters and last 2 characters are switched.
We won't put 004C30 directly.
You'll write 304C00 instead of 004C30.
Now, let's apply it.
I use Hex Workshop v6.7, you can use any other if you want.
Here is the situation after you open it.
Open any xxcrt.o. I open bacrt.o (for Barcelona)
Search for ******FF which repeats. Here, I found mine.
It's C57A00FF. It equals to 007AC5. Wanna see what color is it?
We proved that we need to switch first 2 and last 2 characters. Now I pick any color. Let's randomize; B4590C.
We'll switch 0C and B4. It now became 0C59B4.
Let's come back to Hex Workshop. From Edit tab, open Replace.
Write the colour you want to remove in column Find and you want to make in column Replace. Click OK, which is Tamam in Turkish.
There should come 4 options. Click Replace All.
It's done!
Then save it. You know how to.