Unlike Adlib for Windows, Axiell Collections doesn't offer a lot of customization options where it concerns the colouring of user interface elements yet. The default background colour of displayed screens is now set to white. The renderer will ignore any background colors set in the Screen editor (for screens, labels as well as fields). Label text (foreground) colouring is honored though, but you should ensure that the colour that you choose meets accessibility requirements for contrast (https://webaim.org/resources/contrastchecker/). Other label font properties are ignored.

So it's possible to apply a colour to text on individual field labels. This way you can stress the importance of certain fields, for instance. Colours that you've set for individual labels will normally not be overwritten by colours that you've set on a different level.
Open a screen that you wish to change, in the Screen editor of Designer. Right-click a label and choose Properties in the pop-up menu that opens. The properties of the label will be opened. At the bottom of the first properties tab you'll see the Foreground colour option and an example next to it. Click the relevant coloured box to open a standard Windows colour picker from which you can choose a new colour. Click OK to copy the selected colour to the field label and close the properties dialog. Save the changes to the screen, recycle the Collections application pool in IIS and log in to Collections again to view the result in the detailed display of the screen.