(According to Adobe Photoshop 6.0)
Open Photoshop
Upload your image by selecting "file" at the top, and "open"
after selecting your picture,
On the top of your screen, click "image"
then click "adjust"
then click "desaturate"
(if desired,
play around with tone of picture
by selecting "image"
"adjustments"
and then color balance)
on the left of your screen...the tool bar...
click the dash line box
click your mouse from one corner of you image
and drag your mouse to the opposite corner,
click "file" then "copy"
then click "file" and "open"
once your original picture is on the same screen,
and you clicked the original picture so that
it was the most recently clicked one...for this to work
click "edit" and then "paste"
On the left sidebar,
there should be an eraser shape
near the paintbrushes
click the eraser.
you can adjust your paintbrush size by
clicking the small down arrow
which is located next to the big black dot
with the word "brush" by it.
anywhere you want color,
draw on the most recent image you uploaded.
If you make a mistake,
click "edit"
then "step backwards"