Custom Selection Box [1.8] [1.7.10] [1.6.4]
Now in the settings there will be a new item that will allow you to change the color, transparency and scaling of the selection of blocks.
How to install Custom Selection Box Mod:
1. Download and install Minecraft Forge
2. Download mod
3. Open the file using the archiver.
Select the version of the mod and copy it
(without unpacking) to C:\Users\USER_NAME\