Again sorry for delay - just saw this. Let's say someone has a...

Again sorry for delay - just saw this.

Let's say someone has a bid for 100k shares @ at 6.8c (so someone put in a buy order with a max price of 6.8c) and someone has an 'offer' or 'ask' for 200k shares at 7c (someone put in to sell 200k shares min price of 7c). This is called the spread.

And let's say last sale was at 7c. Someone can come along and buy 50k shares 'at market' or with limit of 7c and you even though they are buying, the volume bar stays grey, because it is the same as the 'last price' it traded at, which was 7c. If someone then bought 200k shares at market it would suck up the remaining 150k at 7c and then eat into whatever the next best offer is (would usually be 7.1c). If there was only 30k available 7.1c and 300k at 7.2c then it would trade 30k at 7.1c and 20k 7.2c. Last traded price would be 7.2c and assuming no other trades in the timeframe the volume bar would show as green because price has moved from 7c to 7.2c. Hopefully this makes sense on how buying and selling can occur whilst price can actually remain the same.