[Stuck in grayscale]

Thanks, I was able to figure it out on my own by creating a new pixil layer, Document>Color Format>RGB.  Sorry for taking up your time, Kim

[Stuck in grayscale]

Newbie here.  I use affinity photo to adjust old documents (ie deed and probate records from the 1700's) so they can be read more easily.  I would like to underline the document in certain areas in red.  However, when I use the pen tool to create a line I can only adjust the line in gray I can't seem to make it red.  I've tried to add an additional layer but it still will only let me modify the line in shades of gray.  I need to underline parts of the document in red for genealogical purposes.  I was hoping someone could take me by the hand and lead me through this.  Thanks so much.