As reported by Jen Gentleman on Twitter, a new update for the Sticky Notes will be rolled out soon or probably rolling out now. The app would be bumped to version 188.8.131.52 after the update.
The update as mentioned in the tweet brings changes to the UI of the colour picker which is now shown with square previews for the colours compared to the round previews prior to the update. The Settings icon is also moved from the bottom left to the top right side along with the colour previews. The new update also adds an option to change the font size in the settings.
Sticky Notes is really a helpful tool to note down important things and reminders and its good to see Microsoft is continuously improving the app.
When available, users can download the new update from the store by clicking the link below.