Changing colors of strokes afterwards about android-quill HOT 3 OPEN

I like this idea as well, but I might implement it differently.  With 2 helpful 
additions.

1. The ability to send strokes forward and backward (front and back).  
2. Introducing opacity/transparency to color

How could it work?

1. Select a highlight color (yellow maybe and lower the opacity so it isn't 
glaring).  Thicken the stroke and stroke over the word.  Part of the word/text 
should still show because the highlight is transparent.  
2. Touch the highlight which brings up a small menu to "Send back" or "Send 
forward".  Tap send back and it pushes the highlight behind the word. 

Just an idea, but it implements 2 powerful vector tools.

I like the idea with.the opaque highlight color! That would be VERY useful to 
me!

I like the OP's suggestion and the first commenters suggestion. As far as 
implementing changing color strokes, the way I would implement it would be as 
such: 
(within this suggestion is an implicit suggestion that you incorporate a 
multi-purpose "lasso/square shape tool" into the tool bar)

1) Select lasso/ square shape tool button on the sidebar.
2) (A little square icon and a lasso icon now pop up from where you initially 
pressed) Choose either or, and then select the portion of the paper which 
concerns you.
3) As soon as selection is done, a popup menu appears.
It gives you these choices: copy, cut, delete, highlight, change text color.
4) You would select change color (a tint in the interface over where you 
square/lasso tooled would give you the indication that the particular section 
is under construction).
5) Lastly you select the desired color, the tint goes away, and voila! New 
color for the strokes which were previously another color. [Note: this would 
work similarly with highlighting]

Oh yeah, as far as highlighting... why not just incorporate a highlight button, 
and have a way to set your desired opacity?