Fix #18 - Make colors more future-proof

[papjul]

This PR should fix #18, by making colors based on the final release date of the SDK version.

Final release date	Color
< 1 year	Green
< 2 years	Blue-green
< 3 years	Orange
< 4 years	Red-orange
> 4 years	Red

That way, it should require less app maintenance (if none of us is there to do the yearly maintenance of targetSdk), and if Google keeps the same release pace, colors should be good for about 2.5 years (up to 2027 Q2 if a SDK 37 is released in 2026 Q2).

Note that since SDK 32 and SDK 33 were released at about the same time, they are now showing as the same orange color, which is the intended behavior if we are based on year since release.