A style is used in ArcGIS Pro to store a collection of design elements such as symbols, colours, colour schemes, label placements and layout items. These elements can then be both managed and used repeatedly in maps, scenes and layouts, which saves time and creates uniformity between projects. A style can be stored individually within a project, in a shared location (e.g. a network folder) or in an ArcGIS Portal. As a result, styles can be copied and shared between different projects and users to help create a consistent cartographic and visual appearance for maps across many projects. Styles within an ArcGIS Pro project can include system styles (i.e. those built-in to the software – it is worth noting that there are more available to add to your project than are displayed by default), custom style (user-created, any non-system style), web style (shared to ArcGIS Online or Enterprise) and mobile style (for mobile apps). There is further information on the types and functionality of styles here.

How to add styles into ArcGIS Pro

You can create your own style from scratch. Better still, there are many styles readily available to download from ArcGIS Online to give you a head start. In this blog, we’ll focus on some of these downloadable, ready-to-use symbology sets for 2D mapping. One good source is Gallery for Esri Styles, which categorises those relevant to science, the environment, utilities, business and transportation, to name just a few, tailored to symbolise data commonly used on those industries in a more meaningful way.

Once downloaded, a ‘.stylx’ file appears in the Downloads folder. This file type is compatible with ArcGIS Pro. After saving to an appropriate folder, the style can be accessed from an ArcGIS Pro project using the Catalog View (or Catalog Pane). To bring the stylx file into a project, right-click on Styles. Three options appear with choices to Add, create New or Import a style. Select New to copy elements of styles from elsewhere into a new, empty style or to create a style from scratch. Select Import to bring in an existing style from ArcMap, which is then converted into a style file for use in ArcGIS Pro. Here, we focus on how to add a style by choosing Add, as shown in the image below.

An alternative way of adding a stylx file is via the ribbon by selecting the Insert tab, navigating to the Styles group and clicking on the dropdown arrow next to Add:

Navigate to the folder where the style has been saved and add it to the project. Depending on the version of ArcGIS Pro being used and the style that has been downloaded or copied for use, there may be a prompt to upgrade the style when adding it to the project. Selecting ‘yes’ to the following message will upgrade the style to make it editable and the original style will be saved (e.g. with a 2x at the end of the name) in the same location as the upgraded style:

Once added, the stylx file can be accessed in the project Styles folder, along with other pre-installed system styles, from the Catalog Pane (or Catalog View).

To view the contents and properties of the added style(s), open the Catalog View (located in the View tab on the ribbon), select the relevant style from the Styles folder in the Contents pane. The properties for the style will be displayed in the main Catalog View window as shown in the image below.

An additional tab, Manage, appears on the ribbon when selecting Styles in the Catalog View. From here, the style can be organised, managed and added to. For example, an extra symbol (e.g. point, line, polygon) can be added to the style by clicking the New Item dropdown arrow. To view the style contents, including any newly added items, double-click on the style name. Properties can be added to each item / symbol by selecting it and populating the necessary information. Pre-installed styles, e.g. ColorBrewer Schemes (RGB), cannot have new items added to them.

To apply the style symbology to a layer in a map, open the layer Symbology properties, browse the list of symbols, or search for the relevant symbol name in the Gallery. Note that you can group symbols by Style or by Category, as well as configure various options for their display.

Symbols grouped by Style

Symbols grouped by Category

Top 5 ArcGIS Pro Styles for Geoenergy

What are some of the styles we’ve found useful in the work we do in Exprodat? Here are my top five…

Wellbores

There are many different well types, and it’s often useful to display both the status and type of well. A specific set of symbology helps to identify wells when displayed on a map. The Professional Petroleum Data Management Association (PPDM) provides a collection of standardised symbols to represent wellbores. Whilst not as extensive as the list of wells symbols in the Shell style (see next section), it does provide a recognisable and understandable standard across the industry. The meaning of the symbols is, therefore, unambiguous and usage of the symbols does not vary from one map to another. The PPDM symbology can be downloaded from Esri’s Industry Styles Content. The image below shows some of the symbol options currently available for use in a project.

Petroleum

For data related to the petroleum industry and its activities, Shell has created an industry standard style, which is available for use in ArcGIS Pro. The Shell Standard Symbology 2016 is divided into a Green Oil style and a Red Oil style, both of which are available to download from the Esri Industry Styles content page. The distinction reflects convention for symbolising oil and gas fields as red or green by different regions and governments (a bit like the convention for green or blue being the colour for cheese and onion or salt and vinegar crisps in the UK!). Each style adheres consistently to one colour scheme and organises the symbols according to themes such as hydrocarbons, geology, geochemistry or wells. The two images below show a snippet of the green and red oil symbology available for use in ArcGIS Pro.

As you can see, there is a wide range of symbols – approximately 1,000 – for everything from natural features, like bed thickness, source rock types and chronostratigraphy, to man-made features like wells, pipelines and other infrastructure, to locations like survey extents and road hazards. Note that some symbols use font characters that are not part of the standard font set. To access those symbols, 22 TrueType Font files will need to be downloaded and unzipped in the home folder location.

Mining

As well as third parties like PPDM and Shell, Esri produce their own styles. This Esri style for mining includes symbology for rare Earth elements (REEs), key to the energy transition, and important for critical mineral exploration and corresponding data. There are also meaningful symbols easily recognisable to the mining industry, which represent features located at prospect or active mines. The style also comes with specific colours (found in the Properties tab of the Symbology pane), which represent geological time periods where some, but not all, correspond to the ISC Chronostratigraphic Chart. Hover the mouse over each colour to see which time period it represents.

Power plants

One quick one before we dive deeper into the final style. For Geoenergy projects, including thermal, renewables or power plants, I like the PowerPlants style from Esri. It offers intuitive symbology – the symbols are attractive, taking the form of simple cartoon images of power plants or energy methods that are appropriately coloured, making them easy to understand by non-experts and experts alike.

Scientific colour ramps

Most of the examples above refer to symbolising vector data – i.e. point, line and polygon feature classes. Equally important is how raster data is symbolised, particularly where they represent continuous data, such as elevation and horizon thickness (rather than discrete data, like land cover type). In these instances, colour ramps are used to symbolise the data. However, standard colour ramps, involving the use of familiar rainbow colours e.g. with dark reds at one end, brighter yellows and greens in the middle, and dark blues at the other end, may prove unhelpful when it comes to depicting numerical differences in data.

The dark-light-dark presentation of rainbow-style colour ramps may become meaningless for colour-vision deficient or colour-blind individuals if the aim of the colour scale is to display a continuous or discrete change in numerical value from low to high (or high to low). Crameri et al. (2020) explain how what is seen is black/ dark grey colouration at one end of the scale, followed by light greys to white in the middle, rounded off with more dark greys or black at the end – the image below provides a good illustration of this problem. For a deeper dive into this issue, refer to this Esri blog.

In addition to the difficulties of interpreting the value of the colours, standard (out-of-the-box), colour ramps can also be perceptually non-uniform. For example, the changing colours do not represent a consistent, increasing or decreasing, change in the actual value of the data. The image below shows a non-uniform increase of values that correspond to the standard rainbow colour ramp. As you can see from the guiding numerical scale at the top, it is very difficult to accurately determine the values assigned along the length of the colour ramp.

(Credit: Lindsey Smith)

The use of perceptually uniform, scientifically-derived colour maps, designed on principles of human vision and colour perception, improves the visual problems of perceptually non-uniform, standard, colour maps by equally weighting any variation in data value across the colour ramp. It also uses different colours to show genuine changes in the data by placing darker colours at the beginning (or end, if reversed) and lighter colours at the end of the colour map Crameri et al. (2020). A scientifically-derived colour map, Scientific Colour Maps 6.0 (Crameri et al., 2020), can be downloaded for use in ArcGIS Pro as a .stylx file from Esri here. The image below shows the colour map options available. It also contains colours that are lighter in the middle of the scale, which are appropriate to use if the data varies around a central value (e.g. zero), where the colour map needs to differentiate between the two sides of the axis.

ArcGIS Pro also has a pre-installed style, ColorBrewer Schemes (RGB), based on ColorBrewer, developed by Cynthia Brewer and Mark Harrower, which offers scientific colour ramps for both continuous and discrete data. Furthermore, if managed in Catalog View, a search for ‘color blind’ (note the US spelling) will reveal all colour ramps that can be interpreted by colour-vision deficient individuals.

A further set of uniform colour maps for use in ArcGIS Pro is provided by ColorCET (Kovesi, 2015) and can be downloaded from this website as a ‘.stylx’ file. The image below shows a small sample of the colour ramps available for symbolising data.

As an aside, if you’re a Petrel user, one additional way to standardise the symbology of your subsurface grids is to use Exprodat’s Data Assistant add-in, which allows you to import the Petrel colour ramp into ArcGIS Pro when you import the grid.

Summary

The use of styles in ArcGIS Pro leads to a consistent cartographic and visual appearance across maps. As well as sharing styles via a flat file .stylx, they can be shared as Items via your ArcGIS Online and ArcGIS Enterprise to make them more widely findable and downloadable to your organisation. The Esri industry styles are a good repository for domain-specific symbols. Elsewhere, there are styles provided as a component of a wider package, such as IOGP’s SSDM or OISDM. The scientific colour ramp issue is one I’ve found interesting digging into. I’d urge you to investigate how using some of those referenced above changes the display of your data.

What other styles do you find useful? Are there any missing that you think the industry should provide? If you want help with styles, or any other aspect of the ArcGIS platform, please get in touch.

Posted by Samantha Faircloth, GIS Technician, Exprodat: A Getech Group Company

KeyFacts Energy Industry Directory: GETECH