Effect of "Thran Lens" on Devotion
Mana cost and color are two completely separate characteristics. Thran Lens only modifies the color, not the mana cost, and so Thran Lens has no effect on devotion.

Devotion


  700.5. A player’s devotion to [color] is equal to the number of mana symbols of that color among the mana costs of permanents that player controls.


Mana Cost


  202.1. A card’s mana cost is indicated by mana symbols near the top of the card. 


Color


  202.2. An object is the color or colors of the mana symbols in its mana cost, regardless of the color of its frame.
  
  202.2f Effects may change an object’s color, give a color to a colorless object, or make a colored object become colorless