看起来绿色是 Ubuntu MATE 的默认颜色。突出显示的文本为绿色，条形为绿色，等等...如何将其更改为其他内容？
当我运行sudo apt-get dist-upgrade它时，它会在最后输出以下内容：
The following packages were automatically installed and are no longer required:
linux-headers-4.2.0-16 linux-headers-4.2.0-16-generic
linux-image-4.2.0-16-generic linux-image-extra-4.2.0-16-generic
Use 'apt-get autoremove' to remove them.
我可以自动删除这个吗？