Tab usage visualization: reexamination of the fan-shaped view

When we further discussed details of the fan-shape View of what opened what, we experience tradeoffs among features we wanted to represent. An important decision was then made: discard the representation of tab age indicating by color. Too many colors would dilute each’s importance though visually appealing, thus we decided not to misuse this significant representational element; instead, we chose to use the size to represent the total amount of time spent on tabs, i.e., more time you spent on a tab, the longer that tab would be. We reexamined how we previously represent what opened what and added a new feature in our visualization: history of current open tabs. Here comes our redesign of the fan-shape view:

As can be seen in Figure 1, the color is now used to represent the current state of tabs: yellow shows tabs recently in use; gray indicates tabs not used for a while; dark gray represents a history of previously opened pages within current tabs. The margin is set in between tabs to show new tabs open, whereas those without margin (dark gray ones) represent the history of that tab.
In addition, we considered the chance that people might open tabs out of the blue, meaning pressing Ctrl+Tab or right clicking “open new tab”. One possible way to solve this problem can be seen in Figure 2.

V2 & V3 represents two totally different tab organization of the fan-shape view from the original one. Clicking on any of them will replace the current fan-shape view.
We wish this view wouldn’t bigger than half of the browser window, which will look like Figure 3:

One problem is still in the face of us: how do we show these tabs’ thumbnail/icon? We think of the regular rectangle thumbanil way to represent them, but not satisfied with it. Hope we will come up with better ideas in the future!