Picture not accepted because of technical issues

Too dark, no color.  Coleus has brightly colored foliage which you have not captured here.  IMO, no amount of editing can fix this. 

Before you submit, compare your work with other Stock inventory in the same keyword category to see how yours holds up against the competition. 

https://stock.adobe.com/search?k=coleus

If your work is not significantly better, chances are it won't be accepted.  Also plants are a fiercely competitive category and you probably won't make many sales.

Best advice, find other subjects to photograph that will give you better earning potential -- i.e. people, places, real life situations.  The best stock images evoke emotion and tell a story. 

Better luck next time.

Starting with the histogram:

You see clearly, that the blacks (left) and the whites (right) are missing. This makes the flat look that your image has.

Looking at your picture at 100%, you see that painterly look. The picture has been taken at ISO713, for me, that is a first. I've never seen something like that. But anyhow, the camera software has “optimized” out all noise, leaving only that painterly look, where you should have a nice structure.

This should look naturally like a plant's leaf.

All in all, your picture looks like a typical phone picture that has been edited using one of those fancy filters. You really need to keep in mind, that the aim of stock is to get naturally looking pictures. If the buyer needs a filter, he or she can apply that, but it will be difficult to restore a natural look with such an over processed image.

There are several issues. Regardless as to how many times you have edited the photo.

1. The table edge is not level.

2. The flower needs to be a little crispier. Better focus.

3. The photo is slightly underexposed.

4. The white balance is to cold. The photo is blue.

5. The lighting is bad. Shadow on the wall and on the container is disturbing.

6. The cropping is bad. Too much of the flower is cut off. Too much foreground. Use the rule of thirds!

I hope this helps.