Hand lapping valves

Just finished my first head and have a couple of questions . Is it normal for the smaller exhaust valves & seats to have a much smaller grey line ? All four exhaust valves came out the same but are about half the thickness of the line on the intake valves & seats which also came out the same as each other . They all also came out the same consistant colour and line thickness with no pitting or scratches etc so is that allI really want from this process or should I keep going until the exhaust valves& seats match the intake ?