Anemones have two types of coloration. They have their natural pigmentation (which can be many different colors, and even two or more colors on the same anemone) and they have the coloration they get from their zooxanthellae, which is ALWAYS a milk chocolate brown color.
Normally when people say an anemone "bleaches" they mean it expels its zooxanthellae, or the zooxanthellae dies off.
Bleaching can also be caused by starvation in a low nutrient environment (like in a store tank that doesn't get food). Zooxanthellae need nutrients (nitrogen, phosphorous, etc) that can be obtained from waste products from the anemone, or from the water around the anemone. If there are no nutrients in the water, and the anemone is starving and not producing waste, the zooxanthellae begin to starve EVEN IF there is plenty of light.
This anemone is starving and partially (not totally) bleached. Get it into your tank and start supplementally feeding it tiny bits of food.