Top layer and Top solder layer Altium
Top Solder is the Soldermask (you need to interpret it as a negative layer, violet means no soldermask, empty means soldermask), not your actual pad (that's the Top Layer, positive Layer, red = copper, empty = no copper).

Yet, you could get problems with solder quality if you do not have solder mask between your pads as the solder might easier make shorts between to pins. Maybe you could make your pads a bit smaller to increase the distance which would in turn add soldermask between them.