Create a layer mask of a Logo

[ProfoundHypnotic]

Hello,

I need to upload a mask to my shopify store for my clothing products so I can have a live preview of a chosen color on the product. my question is, can someone point me to documentation on how to make a layer mask of a logo that is on an image? I've tried googling the solution but I may not be using the right terms because I can't seem to find what I'm looking for. 

so for example, I have uploaded a picture of one of my hats. I have a 10 main colors that the Hat can be but the logo can be any color. Rather than uploading a ton of different images I am trying to have one picture for each product and then have the color previews so users can choose their color scheme. so how can I go about creating a mask of the logo on the image attached so I can upload to to shopify for the live preview? 

Here is a youtube video of something similar to what I'm looking to do. from 0:45-0:50 is what I am looking to create but for the logo attached. 
https://www.youtube.com/watch?v=GM63x8NKL68&t=55s


I really hope all my ramblings made sense but if not please let me know so I can clarify. 

Thanks in advance for your help!

[Krikor]

Select the logo;
Create a new transparent layer;
Create a selection mask on that layer;
Optionally lock the Alpha Channel of that layer;
Now just paint this layer with the desired color.
   

[mholder]

EDIT....I misunderstood the question...nevermind

[Ofnuts]

• Add an alpha channel if not there yet
  
• Set the paintbrush tool to Color erase mode
  
• Paint over the logo in white, this will make it transparent
  
• Can't tell exactly what you want as a mask, but it is likely the alpha channel of the resulting layer, or its inversion.