How do I clean a coloured, plastic kitchen sink?

DH and I recently moved to a house that we are renting. The sink in the kitchen is plastic and peachy coloured.

It is starting to develop gross dark spots. I don't know if they are mold or what.

I don't know what to clean it with. If I use bleach it will ruin the colour.

Since it's a rented house, I can't change anything or replace anything. I am stuck with that sink.

How do I clean it?

I think as long as you don't let the bleach soak into the plastic, it shouldn't do anything to the colour.  Plastic doesn't react quite the same way fabric does to bleach in my experience.  

Have you tried  baking soda or vinegar?  That's usually good for removing stains from the plastic microwave containers, maybe it'll work on the sink?  

I have a plastic sink in my bathroom at my mom's, and I clean it with the same stuff I clean the walls of the shower with. It's some kind of "no scrub" spray. Works pretty well.  

I've also used toilet cleaner on my bathroom sink because it was the only thing I happened to have around at the time.  

I'd also consider using a dish pan in the sink in the future.  

You could try mixing baking soda and liquid detergent into a paste, and using that like Soft Scrub.  I'm not sure if it would do anything for the dark spots if they are mold, but it's a good all-around cleanser.

If you do think it's mold, and can't use anything bleachy, you could try vinegar instead.  I don't think it would discolor the sink, but it might be worth doing a very small spot test somewhere inconspicuous first.  Another suggestion from natural cleaning sites I've checked is to use tea tree oil.  It's recommended that you mix about 1 teaspoon of oil with a cup of water and spray on.  If that doesn't work, you could try upping the strength, or even dabbing on the pure oil.  Again, though, I'd recommend spot-testing.