PlainTasks is an open source and opinionated Sublime Text todo-list plugin, which means that it is highly configured to look in a specific way.
But this does not mean that you can not customize it. If you feel that something does not look right and you want to change it, you can easily do it in your user settings file.
Go to Preferences > Package Settings > PlainTasks and open Settings - User, there you can override all the default settings. to get an idea you can take a look at Settings - Default.
Bring up the command palette (it's ⌘ + shift + p in OS X and ctrl + shift + p in Windows) and type task and select Tasks: New document command.
Detailed installation and usage instructions for the PlainTasks Sublime Text plugin are available HERE.