Step 6-
Color the
1/4 tone layer
Select the 1/4s layer and highlight the image. Click on the middle check box to write-protect all layers except the one you want. This allows you to select the target layer, in this case the 1/4 tones, by simply clicking anywhere on the image composite.
With the layer selected, open the Color palette and set the line color at a bright red, in this case: R-255, G-47, B-31.
