Archaeplastidia

You are eaten by a corticata.  It thinks you are tasty food.  Luckily, over time, it has been letting lifeforms like you live on inside it for a little while, because you can continue photosynthesising and making sugar while inside.

In fact, it has evolved to provide the chemicals you need as food to extend your life inside it.

This adaptation has now reached the point where it can contain multiple photosynthesing bacteria, and they can live on inside it indefinitely.

You have entered a symbiotic relationship, and will never live outside again, getting food and protection, for the price of a few sugars.

Inside your host, you photosynthesise using a chemical called 'chlorophyll a', which turns you a blue-green colour and gives you a supply of sugars all the time you are in sunlight.  It doesn't absorb all the sunlight though - only a part - the rest is wasted.

The usual copy-error effect can give you the ability to make a slightly different version of chlorophyll which will work using a different part of the sunlight spectrum, but it means you'll make less of chlorophyll a.  Interested?

I'll go with two.
The one I have is just fine.