NIWA has a default style guide, created in conjunction with communications team and IT systems development but the repo I found for R Shiny Apps still used the old logo so I forked NIWA's shiny_styleguide and use some basic css to copy NIWA's current style.
The file style.css
contains basic css code for some of the elements defined in ui.R
.
Here's a screen shot of the a basic R Shiny app with my updated NIWA style.