How to Customize User Profiles with Style Variables
 

The format is as follows:

[Category] (General, etc.)

[Profile area name] (Title Text Color, etc.)
Controlled By: [variable that controls the area]
Note(s): [if needed]
[Screenshot(s) of the area]

I do not have a screenshot for Module Link Color.

General:

Title Text Color
Controlled By: body_color

http://i.imgur.com/5jWrrvs.png

Page Background:
Controlled By: body_background

http://i.imgur.com/A49lhkH.png

Page Link Color:
Controlled By: link_color
Note: Also controls Content Link Color.

http://i.imgur.com/Va28H9k.png

Modules:

Module Text Color
Controlled By: blockhead_color

http://i.imgur.com/NpdNFgW.png

Module Link Color
Controlled By: blockhead_link_color

?

Module Background
Controlled By: blockhead_background

http://i.imgur.com/YxfNeSI.png

Module Border
Controlled By: blockhead_border

http://i.imgur.com/n7ICxyu.png

Inactive Modules:

Inactive Module Text Color
Controlled By: sidebar_header_color

http://i.imgur.com/KapWnQi.png

Inactive Module Link Color
Controlled By: sidebar_header_link_color

http://i.imgur.com/AoGwzNI.png

Inactive Module Background
Controlled By: sidebar_background

http://i.imgur.com/2Qfl113.png

Inactive Module Border
Controlled By: sidebar_border

http://i.imgur.com/qSvxdkB.png

Buttons:

Button Text Color
Controlled By: control_color

http://i.imgur.com/AwLvTOG.png

Button Background
Controlled By: control_background

http://i.imgur.com/bo8KE0d.png

Button Border
Controlled By: control_border

http://i.imgur.com/Vm7UDkH.png

Content:

Content Text Color
Controlled By: postbit_color

http://i.imgur.com/eFSOHUr.png
http://i.imgur.com/ja8NpwP.png

Content Link Color
Controlled By: link_color
Note: Also controls Page Link Color.

http://i.imgur.com/48niEFZ.png

Content Background
Controlled By: postbit_lite_background

http://i.imgur.com/SXItAXO.png
http://i.imgur.com/lUAkxRZ.png
http://i.imgur.com/t52I1AI.png

Content Border
Controlled By: postbit_lite_background
Note: This is also controlled by the postbit_lite_background variable, which seems to be a bug. There should be a postbit_lite_border variable.

Headers:

Header Text Color
Controlled By: postbitlite_header_color

http://i.imgur.com/6Qa3xR4.png
http://i.imgur.com/oxXHAeF.png

Header Link Color
Controlled By: postbitlite_header_link_color

http://i.imgur.com/wOcA2gQ.png

Header Background
Controlled By: postbitlite_header_background

http://i.imgur.com/ZnD2Qvq.png
http://i.imgur.com/XrIkL8k.png

Header Border
Controlled By: postbitlite_header_border

http://i.imgur.com/1mxNXXN.png
http://i.imgur.com/xJAp9Lq.png

Thanks for sharing @Amaury. I am adding it to my reference list.