How to have different colors in each Terminal window Can I do this? 

OMG, I looked for hours, and every article I find tells me how to colorize the output of ls. Or colorize my prompt. I really really really don't want that. 

I want to colorize the text. The default text in the terminal window. 

I know I can do this from Terminal Preferences. But that applies to EVERY terminal window that's open, which I don't want. 

As the subject says, I'd like to have three different terminal windows with three different default colors for text in them. How can I do that?

In Windows cmd.exe, I could run a command from the prompt: color 0xA 0xG (something like that) and it would re-colorize the basic text and background. rather that pointy-clicky inspector themes menus and all that... can I do something like this from the MacOS Terminal prompt?
I may not be understanding the question fully, since you change the color settings per-tab/window contrary to your question, but here is how to do what I think you want.


Go to Terminal menu > Preferences.
Click on the Settings tab.
Click on the gear icon at the bottom left and choose Duplicate Settings.
Enter a name for your settings.


Make any changes you want to font colors.
Repeat steps 3 through 6 until you have as many sets of colors as you want.
Close the Preferences window.
Open as many tabs as you want (3, it sounds like).
Right-click on the first and choose Inspect Tab.


Select your desired Settings pre-set from the list. (The ones you created will be down towards the bottom.)
Close the Inspector window.
Repeat steps 9 through 11 until you have customized each tab.


That should be it. If you want Terminal to always open like this, with these three tabs and their associated color settings:


Go to Window menu > Save Windows as Group.
Enter a name.
Click Save.
Go to Terminal menu > Preferences.
Click on the Startup tab.
Next to "On startup, open:" choose the radio button for "Window group:" and select the name of the group you created in step 2.