With the latest release of Chrome (i.e. 69), Google browser, a new design was introduced. Chrome now has square tabs for example, and somewhat different colours are used as well (i.e. lighter colour scheme).
However, you may dislike this new Chrome layout. You may think: how to go back to the old Chrome? Since you prefer the old Chrome design, you can luckily revert back to the old Chrome design quite easily in a small number of easy to follow steps. Follow the instructions below:

1) First, go to chrome://flags/#top-chrome-md in the Chrome address bar
2) Then, find (via CTRL+F) the “UI Layout for the browser’s top chrome” flag and change it from Default to Normal.
3) Lastly, you should now restart Chrome

You will see that you now again have the old Chrome tabs and other design back as before the upgrade to Chrome 69.