Current web standards have facilitated the online production and publication of thematic maps as a useful aid to interpretation of spatial data and decision making. Patterns within the raw data can be highlighted with careful styling choices, which can be defined for online maps using tools such as Styled Layer Descriptor (SLD) XML schema. Dynamic generation of maps and map styles extends their use beyond static publication and into exploration of data which may require multiple styles and visualisations for the same set of data. This paper explores the application of thematic styling options to online data, including mapping services such as Open Geospatial Consortium (OGC)-compliant Web Mapping and Web Feature Services. In order to be relevant for both user-specified and automated styling, a prototype online service was developed to explore the generation of styling schema when given data records plus the required output data type and styling parameters. Style choices were applied on-the-fly and to inform the styling characteristics of non-spatial visualisations. A stand-alone web service to produce styling definitions requires a mechanism, such as a RESTful interface, to specify its own capabilities, accept style parameters, and produce schema. The experiments in this paper are an investigation into the requirements and possibilities for such a system. Styles were applied using point and polygon feature data as well as spatially-contextual records (for example, data that includes postal codes or suburb names but no geographical feature definitions). Functionality was demonstrated by accessing it from an online geovisualisation and analysis system. This exploration was carried out as a proof of concept for generation of a map styling web service that could be used to implement automated or manual design choices.