I confirm the setencias both in the PHPMyAdmin console and in the MySQL console as a separate service
UPDATE frutas SET color = 'rojo';
EXPLANATION
When you use the interactive console of phpmyadmin, it puts an example structure for you to carry out the query; The last thing you show is not an error is the example that this tool provides you.
What you should do is write as you like your query and later in the sql tab and in the lower right corner look for the button that says CONTINUE which will allow you to carry out your massive modification; but be careful what I'm putting it to you
THEN SO THAT MY PHP MYADMIN MAKES THAT EXAMPLE?
Simple is telling you that you are going to make a modification but where the id is equal to 1, look
UPDATE frutas SET color = 'rojo' WHERE id = 1;
That's the only difference, if you use the where you only affect a row and
if you do not use it, it affects all the records in your table
UPDATE
Even if you are working on the php myadmin console, you can use only
for the values that are strings of text or dates the quotes
simple '' you do not need to use inverted ones