Thanks for posting and welcome to FileMaker!
The gray fill with the option to add text is the default design of the Button tool in the tool bar. Unfortunately, when you create a Button in this fashion you do not have the ability to choose from a list of icons. However, aside from adding Buttons to a Layout via the Button tool on the tool bar, FileMaker offers the ability to define fields and objects as buttons, too.
In Layout Mode, right + click (Windows) or ctrl + click (Mac) the object or field and choose 'Button Setup' from the menu. This Button Setup window is the same window that appears if you had used the Button tool. Now, in Browse Mode, if a user clicks on an object or field it will perform as a button.
Alternatively, you can define multiple fields or objects as a button by shift + click the fields or objects and then going to Format > Button Setup.
For your solution, if you had a particular icon that you liked, you can add it to your layout and define it as a Button. If you happen to like the icons used in the starter solutions, you can always enter Layout Mode, copy them, paste them to your solution, and then enter Button setup to properly configure them to your database.
Let me know if you need further clarification. Hope this helps!
Thank you for the reply. I understand now and all is well again. I think I am going to get along with FileMaker just fine.
Have a great day!