These 2 colors have different shades; Solotica Hidrocor Cristal is grey and Solotica Hidrocor Mel is green
Here is how it looks like in natural brown eye color ♥
 
Solotica Hidrocor Cristal
Solotica Hidrocor Mel
Solotica Hidrocor Cristal (left) and Solotica Hidrocor Mel (right)