Please find below the mt4 version translated to prorealtime code:

//PRC_Spec Volume | indicator
//30.11.2016
//Nicolas @ www.prorealcode.com
//Sharing ProRealTime knowledge
//converted and adapted from Metatrader4 version
//http://www.prorealcode.com/topic/volume-display-new-highlow/

if(High>High[1] and Low>=Low[1]) then  //made higher high and higher low -> high bar
upvol = Volume
downvol = 0
neutralvol = 0
elsif(High>High[1] and Low<Low[1]) then //made higher high and lower low -> neutral bar or outside bar
upvol = 0
downvol = 0
neutralvol = Volume
elsif(High<=High[1] and Low<Low[1]) then //made lower high and lower low -> low bar
upvol = 0
downvol = Volume
neutralvol = 0
elsif(High<=High[1] and Low>=Low[1]) then //made lower high and higher low -> inside bar
upvol = 0
downvol = 0
neutralvol = 0
endif

return upvol coloured(0,0,255) as "up volume", downvol coloured(255,0,0) as "down volume", neutralvol coloured(128,128,128) as "neutral volume"

Will be posted to the Library too. Of course you’ll need Volume for the indicator to work (not the case for forex CFD contracts for instance ..). See screenshot attached of the indicator’s result on DAX30.