CoolSculpting fat freeze. My skin was cold but not red enough. Does that mean my skin wasn't sucked by the machine properly?

Post-treatment skin reaction/redness is not truly reflective of final clinical fat pad reduction. There are several variables such as Coolsculpting energy delivered, amount of superficial skin vasculature in area treated. Most Coolsculpting centers adopted the original aggressive protocol of using maximum Coolsculpting energy of 80J/cm2. We have learned from our extensive experience with Coolsculpting technology that utilizing slightly less energy than the maximum have led to equal amount of fat pad reduction with less skin reaction/redness and much less post-treatment discomfort.

If the skin was cold, then you should have been sufficiently treated.  The color of the skin can vary tremendously after the treatment, so just because it was not red does not mean that it was not effective.  

The redness of the skin following treatment does not correlate with treatment efficacy.  One of the great things about the CoolSculpting device is the many checks and balances built into the machine.  If the device senses the applicator was not applied properly or with proper suction, a warning indicator is triggered and the treatment stops.  Everyone's tissue reacts differently to treatment.  Some people are very red and have bruising, while other people have very little redness or bruising.  As long as the tissue was cold after treatment, you can expect results. 

The redness of the skin by no means reflects the effectiveness of the coolsculpting treatment.   If the machine does not have good suction it will alarm and stop the treatment.  I have seen a wide variety of skin color changes immediately following the coolsculpt treatment.  The important thing is was the underlying fat pulled up like a stick of butter, cold and hard requiring massage to get it to lie fat?  If you had this "stick of butter" shape prior to massage that is a much better indicator as to the effectiveness of the freezing of the fat cells than skin color.  

Immediately after a treatment, you can expect common side effects such as redness and firmness in the treated area. There can also be transient blanching and mild bruising. You can also experience some tingling and stinging. However, everyone is different, and not everyone will react the same to the treatment or experience the same symptoms. Your skin not being red enough does not mean that the tissue wasn't sucked by the machine properly. During the treatment, the tissue is being pulled and isolated from the muscle and blood supply, therefore it is completely understandable for the area to not be as red.