I can’t see the blue in Putty , and every time I started it had to go find that setting. I asked a couple people about how to make this the default and the didn’t know. So – I finally figured it out today. When you start putty, it comes up with a list of “sessions” – and the key thing to understand is that there’s a “Default Session” on the first window that pops up. Dunno how I missed this for so long.
So make the changes you want in properties – then come to this tab and save with the “Default Settings” session selected.