To answer your questions I know：
paint mixed with water and put into brine pool indoor. Deepfreeze.
Drill a hole in ice and put lights in. Ice sculpture is made of many small ice cubes.

The color of the ice is transparent. To make the color, they drill a hole thru or cut a slot in between and insert LED strip lights which can change color and then they join the ice with water. It is programmable and they will change the color of the light according to the program. It is rather simple and LED lights is rather commonly use in China. In the ice festival, you can see LED lid tree ( not real tree) along the road.It is extremely cold and I mean really really cold. you might have good thermal pants and shirt but your face and shoe will also be subjected to extremely cold condition. I was there yesterday night at Harbin Ice Festival. The firework was awesome, the ice carving is rather specta Getting there is cheaper if you can take Bus 88 from Daoli. from there, you need to inform the bus driver and thereafter you can alight and walk to the underpass and to your destination. DO NOT BUY TICKET FROM TOUTER ( They promised to sell you ticket which is cheaper than the retail around 260RMB) The ticket at the counter is 330RMB. My advice is to buy from the counter. Another thing is getting back from the ice festival, there will be Taxi asking for more money back to the hotel. You have to bargain with them depending on your hotel location. My hotel is is gugoli road and takes about 40RMB. Remember to bargain with them. ( The taxi people are quite nice people but quite smart in business also...hahaha). HAve a nice trip and PLEASE DO NOT SLIP AND FALL AS THE SNOW IS REALLY SLIPPERY.