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Color and Choropleths

This lab was very interesting as we dived into color theory. 

In the first part of the lab, we created and compared linear and adjusted progression color ramps to themselves as well as a color ramp from the website colorbrewer.org. 


I found, the colorbrewer color ramps are not as rhythmic when compared to the other methods, as they don’t step up at set intervals or rates. However, I don’t think that a set rate is needed to go from color to color. I preferred the colorbrewer ramp because each color was distinct from its neighbors. In the linear and adjusted color ramps, the colors looked too similar to each other and were not distinct enough for each step. I think that as long as the color ramp is moving in the opposite direction of the same color hue, the step rate or interval is not as relevant. When I first was completing the linear step I started with the purple hue option but had a difficult time, as each step in the color ramp looked the same. At one point, I created my own color ramp playing around, with no step rate between the steps. I think this is more reader-friendly as it’s easier to understand. 

The last step in the lab was to normalize the population data for Colorado, USA, from 2010 to 2014. I then created a choropleth map. When choosing a coordinate system, I choose not to use a state plane as there are three different zones within Colorado. I looked into using UTM, but the entire state did not reside within a single zone. My last choice was to use Albers Equal Area Conic. Because Colorado does not reside too far east from the prime meridian, I felt this was a viable option and proceeded with USA Contiguous Albers Equal Area Conic projection.
When choosing the design for the legend, I looked at using 5 or 6 classes but decided to use 5 as 6 classes created a huge skew toward negative percentages. When determining which classification to use I looked at each histogram. I ended up using Natural breaks (pic below), as again, the other classification methods inaccurately overemphasized either side of the spectrum. I decided to use a divergent choropleth design to empathize the negative and positive percentages. I used red and orange to represent negative numbers. Yellow as a “neutral” middle for percentages near zero. And lastly, greens for positive percentages.



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