The theme has become an important part of Gmail since its launch in 2008. The Gmail that we know come up with a simple design, practical and minimalist. This simple design helps the user easily distinguish the inbox and other folders. "We also launched a new Gmail display in November, we introduced the theme of a beautiful HD. We also hear many of you who want to bring a personal touch by posting your own background. So over the next few days we launched a custom theme with two choices, Light and Dark, "said Greg Bullock, Software Engineer Gmail in its official blog.