Olive skin-tone is a 'blend' of yellow/green and is in fact neutral. There is a range of Olive skin tones from light olive, to deeper olive, to golden-olive etc etc
Olive skin-tone is difficult to pin-point in seasonal colour analysis because of the apparent 'yellow' tones. This is not to say that olive skin tone can't lean warmer, but the answer is 'skin-deep' :)
The cool/warm ratio is also difficult to pin-point in the traditional manner. If you go by the vein test where blue is cool and green is warm, olive skinned gals will be lost because we have a blue-green blend that doesn't lean more one way or the other.
Olive skinned gals will often find that they need lipstick shades with added brown, mahogany tones. They look great in reds, wine and dark apricot/peach shades, as well as deeper rose/pink shades.
I was personally torn between many seasons in my search for seasonal colour analysis. However, that being said, every time I was draped in person, I was most definitely an autumn. Yet, at home, I would be drawn to the summer-deep cool shades. My 'olive skin' is the reason for this. In seasonal colour analysis, yes, I am a warm autumn :) However, I feel that if I were to step outside of the sphere of colour analysis, I am most definitely a neutral skin tone that naturally needs brown/mahogany tones (a warm autumn feature), but that also looks great in deep summer hues. In the end, its all about the system that you choose and works for you.
Regardless if you follow colour analysis or not, olive skin is beautiful and the more you can learn/discover about this skin tone, the more prepared you will be to put your best face forward. Here is a look I created that is perfect for my own medium olive skin tone:
For this look I started with a yellow toned concealer and blended in a rose-beige foundation to play up the neutral balance of my skin. I then added back some warmth by applying NYX Ignite/Passion blush (apparently a dupe for MAC Warm Soul blush). I then blended MAC soba and woodwinked and applied this from the lid into the crease. I lined my eyes with Urban Decay Demolition eyeliner and smudged the upper lash line before finishing with black mascara. For my lipstick, I spent some time studying the natural colour my lips turned if I were to pinch them or bite the lower lip. I found that it was consistent with a mahogany shade (which matches my warm autumn seasonal fan). I matched this colour by applying MAC Spice lipliner and then applying NARS Pigalle lipstick :)
I hope that this post was helpful and I look forward to creating and writing more posts about Olive Skin Tone and makeup looks to up-play this skin tone :)