Specific Price? First product discount second normal price?

[Bolonia]

Hi i want to know if i can make this:
Put some discount ej 40% in some product  and when my client buy first product  at 40% but the second , trird , four....  ( in normal price).

 

I have a stock of 3 product in 50% i need sell this fast  so this is hurry for me.

Example :

 

I had  one product Tshirt whit 3 combination ( red - blue -yellow)
I had  10 quantity for red 10 blue  14 yellow.
I need sell the 4 yellow only  at 50%
 

 

Sry my english is bad!
Thank you alot
 

Edited July 16, 2017 by Bolonia (see edit history)