Paint.NET :: Changing Black Tones To White And Vice-versa

1st attempt: Imagine that you have two colors, red and black, and you want to mix 10 drops of red with 3 drops of black. You get a specific color - a weird dark red. Now imagine I have a image with only that solid color and I want to replace those 3 drops of black with three drops of white. How can I do that?
 
2nd attempt: Normal A4 sheets are white, but I want to print a image (with no white or light colors) on a black sheet of paper. I don't need to use a black cartridge, because the black is already there in the paper sheet. How can I remove the "black tones" in order to get proper colors when printing?
 
All this to answer one bottom question, which is also my 3rd attempt on this:
 
3rd attempt: I have access to a modified printer that has white ink on the black ink cartridge; that way, If I write a few words in black and print them out on a black sheet of paper, I'll have a white text. This is very simple if I want only to print text; set font color to black and print, ending with a white text printout. But what if I have a photograph, for example, and I want to print it on a black sheet? If I have a white boat, for example, its' color has to be changed to black. If I want to print a light green, I have to have a dark green on my image. Is there any way to do this?