I am new to using QGIS and for a recent project I am looking at the building heights for London. I have managed to download the free EMU Building Heights Layer and added into my existing file, through 'New Vector Layer', which displays the buildings (polygons) but struggling to get the data displayed to show different colors for the different heights.
There are two possible ways to display building height via colours. Under
layer properties you can either choose
graduated for style. Then you choose the column in the layers attribute table which contains the height-data, fit classes and/or color(-ramp) to your liking and voila.