While the move to Office 365 hosting is great for anyone who uses Outlook to read their mail, many Outlook.com web access users are not happy with the new layout or with the new color scheme.
The layout of my Hotmail account was changed and I don't like the new layout at all. It didn't need changing. The new colors are awful and it's difficult to tell when you have an unread email in your inbox. It doesn't stand out like it used to.
While Outlook.com users can't go back to the old web interface, both Outlook.com and Office 365 users can change the theme if the default colors are hard to see.
To change the theme, click on the Gear icon (in the nav bar, to the left of the user picture or the person icon) and choose Change Theme.
In the theme pane, click on the squares to show a live preview of the selected theme. When you find a theme with colors you like, click OK at the top of the panel to apply that theme to Outlook on the web.