I have unchecked the delete spaces and tabs option, but it refuses to respect this. What else do I have to do?

I'm very happy with the colors I selected for my custom theme, but I have one major issue- The blinking "I" (the text insertion point aka I-beam pointer) appears nearly invisible. I'd like to change its color in my theme, but I can't seem to find a customization option for it.

All edits to the Theme were done by going Tools>Options>LibreOffice>Appearance and using the Customizations dropdown.

Where is the customization option for the text insertion point?

Edit. Well that was as simple as I expected it to be, thank you so much. In the mean time should I spark a conversation about why it does that in the b) case I presented? its very odd.

This may be an incredibly newbie question but I cannot get libre office to do what I need.

I have a data set that needs a number to increment every n rows. The fill handle does not help me here neither do any of the Sheet > Fill Cell options.

Visually speaking lets say its every 5 columns it will look like this;

1,1,1,1,1,2,2,2,2,2,3,3,3,3,3,4,4,4,4,4,5,5,5,5,5,...,n,n,n,n,n

This feels super simple but it just doesn't behave in any way i expect, I even tried expanding the following using the fill handle;

a) 1,1,2,2
b) 1,1,2,2,3,3

But the output is this;

a) 1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5...n,n,n,n
b) 1,1,2,2,3,3,2,2,3,3,4,4,3,3,4,4,5,5,4,4...?,?,?,?

These outputs are incredibly unexpected, I dont think Im trying to do anything super specific and unique here. But im completely out of ideas on how to search this, I hope its okay I come here for help.