Final answer:
The code sequence to return a square of a pale green color with no border is provided using HTML and CSS.
Step-by-step explanation:
To return a square of a pale green color with no border, you can use the following HTML and CSS code:
<div></div>
This code creates a <div> element with a background color of pale green and no border. The width and height properties set the dimensions of the square to 200 pixels each.