スタート画面でデスクトップアプリケーションのタイル（アイコンの変更/拡大、色の変更）をカスタマイズするにはどうすればよいですか？

Those tiles are limited to Modern UI apps. It's possible for such an app to launch normal desktop applications, so all that's needed is to make a simple app that launches the proper desktop application and customize that app's tile.
However, making an app for each shortcut may be a bit annoying. Luckily, one app can have multiple tiles, so called Secondary Tiles. So what's needed is an app that can make custom tiles that launch different programs.

Even more luckily, someone has begun making such a program. It's called OblyTile. This will allow you to create cool looking tiles for non-Modern UI apps (desktop shortcuts).

Features:

• A tile can point to a program, file, URL etc. (with optional arguments)
• Custom background color.
• Custom icon/image.
• Custom small image.
• Custom text (or no text) on the tile.

HOW-TO

Create an PNG image that will cover the entire tile. The size should be 120x120px. This image can have transparency (then the tile's background color will show). Optionally, also create a small version of the image, 30x30px.
My icons for a Firefox icon: small - big
They are white and transparent, so a bit hard to see. On grey background:

Run the OblyTile program.
Fill inn the name of the program, browse for the .exe file (or what you want) and select the two images. Then select a background color for your tile. Example:

This can also be done through command line / batch scripts:

start ob.exe "Firefox" "C:\Program Files (x86)\Mozilla Firefox\firefox.exe" "" "fx_big.png" "fx_small.png" #f58d00 show

いくつかのタイルでこれを行った後（Mail＆Desktopタイルはカスタムではありません）：

そして小さな画像：

タイルを削除するには、タイルを右クリックして選択しますUnpin from start

私のアイコンはこのアイコンパックのものですが、私が行ったのと同じミニマルなスタイルを選ぶ必要はありません。