Improve map feature color palette

[tyrasd]

@felskia wrote:

The orange stands out a bit too much though, it's so bright it feels like the color you should be paying attention to instead of the blue. My recommendation would be:

Highlighted Buildings: Light blue Non-highlighted Buildings: Dark Blue

but:

The issue with using light/dark of the same hue is that these are already in use to indicate different levels of data density at the lower-zoom levels where features are aggregated into cells. Tricky one. Let's continue this in #21

[cgiovando]

Would it make it more consistent to use the same colors for every dataset? Since we switched to layer switcher instead of multi selection...

I would also want to try using a lower resolution grid if possible. This may be as quick as using a higher zoom level for the vector tile overlay than what the map is at. For example, by displaying level 15 of the road density layer when map z=12 it would show a finer grid rendering (less big-squarish).

What do you think @tyrasd - would that impact performance?

[cgiovando]

Something else to consider for inspiration on rendering density at different zoom levels

http://blog.cartodb.com/data-overviews/

It looks like it's open source too, but it may require routing data crunching through PGSQL

https://github.com/CartoDB/cartodb-postgresql/blob/master/scripts-available/CDB_Overviews.sql