I get annoyed when I can’t easily and quickly find the button or other user interface element I need to complete a given task. This is especially bothersome when the task at hand is likely the most common task in a given circumstance.
In this case (see image) I want to send an email. The message is complete and I look for the button to send the email. Of course the button is there, in plain sight. However, visually, the “File” tab and the “Paste” button are highlighted by a bright color, drawing the user’s eye to these locations. The “Send” button, while not small by any means, is a light gray color!
When creating any UI design, be sure to make sure that the most common tasks are the ones that stand out. Don’t make the user hunt… not even for a second.
How many elements can you count on the image that use color? How many of those tasks would you commonly need EVERY time you type and send an email?