How to draw a Monarch Butterfly wing using colored pencils

My sketches for drawing are incredibly rough. I have only a very basic and badly drawn outline and draw most things in freehand as l go.
The reason for this is because if l draw in graphite it dirties the paper and muddies my colours. If l use carbon paper (which l do) it leaves lines that are hard to remove, so l use as few as possible.
So in photo one l started by using only two pencils- a white which you can’t see in the photo. I used heavy pressure to mark out the white spots. And a magenta to mark out a the outline and the veins.
​l chose magenta because if l used a darker colour like black or navy it would dirty the yellows and oranges as l work.

Then l added under layers of yellow and light orange.

Next l used a darker orange and magenta to start adding the shading. Then l redid the veins using magenta.

I then went over the whole wing with yellow to blend it all together again. Then used a darker orange where l wanted shading.

Next l added some hot pink to add a bit of vibrancy to the shaded areas.l also used a bright yellow to add the light line above the veins.

Now l use a darker red violet to define the veins more use darker colours and heavier pressure to build the colour.

Now l use a crimson and hot pink to really add depth, and definition. I use and indigo on the veins.

Now onto the outer wing. I use a base layer of orange and block out the bits I want to remain white using heavy pressure with my white pencil.

Now a layer of Magenta.

Then a layer of a darker red violet.

Now a layer of purple and l also redefine the veins using the same purple.

Next a layer of navy.

First layer of black.

Two more layers of black.

Finally more layers of black. Violet on the veins. A little cream and peach on the white spots and a few white highlights. I also used some more vibrant oranges on the inner wing at this point, as lots of color wears off as l work.