Amazing photograph! Once again, you’ve shown great care in the composition and in particular the color composition of your photograph. By using a limited color range you’ve isolated the more important part of your photograph. For example, the face of the model, and the lipstick in particular stand out to create a nice light highlight to an otherwise dark and gloomy photograph.
Your main subject is strategically well positioned to abide by the rule of thirds and you’ve left more negative space on the right side of the photograph. By “right side” I mean the side the model is looking / facing towards. Using negative space is a great way to enhance your photographs through simplification.
My one recommendation for you, might seem contradictory to what you’ve learnt so far, but what I would like you to try and do is isolate your main object through other means.
Though simplifying through color minimization and composition are two challenging and important concepts to know, it’s also important to know how to ‘organize” chaos. To do this you often have to think about changing your depth of field or your proximity to your object. I’ve noticed you’ve done a great job of “isolating” your main subject. This is something that most photographers have a very hard time doing. However, it’s something that seems to come very natural to you. In your next set of photographs I want to see you draw attention to your main objects through the use of shapes, composition, lighting and other elements other than color simplicity or negative space.
That being said, what you’ve done isn’t incorrect. In fact, it’s a beautiful photograph that you should be very proud of. I just want to ensure that you know how to work within different environments and with different levels of color complexity!