Palettes and Colors

(this is a repost from my Tableau blog: http://tableau7.wordpress.com/2012/04/02/palettes-and-colors/ )

I was always intrigued with colors and their usage, since my mom told me that may be ( just may be, there is no direct prove of it anyway) Ancient Greeks did not know what the BLUE color is - that puzzled me.

Later in my live, I realized that Colors and Palettes are playing the huge role in Data Visualization (DV) and it eventually led me to attempt to understand of how it can be used and pre-configured in advanced DV tools to make Data more Visible and to express the Data Patterns better. For this post I used Tableau to produce some palettes, but similar technique can be found in Qlikview, Spotfire etc.

Tableau published the good article of how to create customized palettes here: http://kb.tableausoftware.com/articles/knowledgebase/creating-custom-color-palettes and I followed it below. As this article recommended, I modified default Preferences.tps file; see it below with images of respective Palettes embedded.

For the first, regular Red-Yellow-Green-Blue Palette with known colors with well-established names, I created even a Visualization in order to compare their Red-Green-Blue components and I even tried to placed respective Bubbles on 2-dimensional surface, even originally it is clearly a 3 dimensional Dataset (click on image to see it in full size):

For the 2nd Red-Yellow-Green-NoBlue Ordered Sequential Palette, I tried to implement the extended "Set of Traffic Lights without any trace of BLUE Color" (so Homer and Socrates will understand it the same way as we are) while trying to use only web-safe colors. Please keep in mind, that Tableau does not have a simple way to have more than 20 colors in one Palette, like Spotfire does.

Other 5 Palettes below are useful too as ordered-diverging almost "mono-chromatic" (except Red-Green Diverging, since it can be used in Scorecards when Red is bad and Green is good). So see below Preferences.tps file with my 7 custom palettes.

<?xml version='1.0'?> <workbook> <preferences>
<color-palette name="RegularRedYellowGreenBlue" type="regular">
<color>#FF0000</color> <color>#800000</color> <color>#B22222</color>
<color>#E25822</color> <color>#FFA07A</color> <color>#FFFF00</color>
<color>#FF7E00</color> <color>#FFA500</color> <color>#FFD700</color>
<color>#F0e68c</color> <color>#00FF00</color> <color>#008000</color>
<color>#00A877</color> <color>#99cc33</color> <color>#009933</color>
<color>#0000FF</color> <color>#00FFFF</color> <color>#008080</color>
<color>#FF00FF</color> <color>#800080</color>

</color-palette>

<color-palette name="RedYellowGreenNoBlueOrdered" type="ordered-sequential" >
<color>#ff0000</color> <color>#cc6600</color> <color>#cccc00</color>
<color>#ffff00</color> <color>#99cc00</color> <color>#009900</color>



</color-palette>

<color-palette name="RedToGreen" type="ordered-diverging" >
<color>#ff0000</color> <color>#009900</color> </color-palette>

<color-palette name="RedToWhite" type="ordered-diverging" >
<color>#ff0000</color> <color>#ffffff</color></color-palette>

<color-palette name="YellowToWhite" type="ordered-diverging" >
<color>#ffff00</color> <color>#ffffff</color></color-palette>

<color-palette name="GreenToWhite" type="ordered-diverging" >
<color>#00ff00</color> <color>#ffffff</color></color-palette>

<color-palette name="BlueToWhite" type="ordered-diverging" >
<color>#0000ff</color> <color>#ffffff</color> </color-palette>
</preferences> </workbook>

In case if you wish to use the colors you like, this site is very useful to explore the properties of different colors: http://www.perbang.dk/rgb/