[How do I change a monochrome layer to a new colour]

@BoltBait thankyou that did the trick. I can totally make a workflow out of that. The process is strangely reminiscent of actually screen-printing. 

[How do I change a monochrome layer to a new colour]

Just gave this a go. Don't seem to be able to anything because I've got no colour to begin with. I can't just amp up the red in the layer cause there is none.

[How do I change a monochrome layer to a new colour]

What I mean is I want to play around with the colour. Try a few different options til it looks right. I observed that as I selected a few different colours the effect was changing. I couldn't go back to a solid black.

 

I looked closer at what colour tint is doing and it's definitely the wrong effect. Looks like it's just outlining the solid colours which is not what I want. And that's why each new colour tint made the colour change weird.

[How do I change a monochrome layer to a new colour]

I want to use paint.net to prepare collages for screen printing . I found a half-tone plugin from Ed Harvey and that works great. I was quickly able to process an images into B+W halftone layers which is what I need to do for screen printing.

 

https://imgur.com/a/czAr8eG

 

What I want to be able to do now is manipulate each layer so that they are temporarily coloured to simulate what the final artwork will look like. eg in my example above maybe I want the lips to be red and the moon to be green. I need to be able to do this in a non-desctructive way because when I'm done I'm going to print out a black and white for each colour/layer I want to screen print. This should be easily done by deselecting layers and changing the colour to black. I just need the right effect that will change all the colours in a layer to be something new.

 

I went through each of the colour effects. Colour tint seemed to be close to what I wanted but it seemed like every time I changed it it would tint the next choice somehow. Anyone able to help?