Differences Between Estetica's RTH613/27 and RT613/27:

RTH613/27 and RT613/27, are the same colors basically, but the H in RTH613/27 means that it is a highlighted shade, whereas RT613/27 is more of a blended shade.

The highlights in RTH613/27 make the color seem lighter than RT613/27, but both colors use the same base color and tones overall. 

You can watch Heather's in-depth color spotlight on RTH613/27 here:

https://www.youtube.com/watch?v=CPaeIhAIOW4