SP penalty?

I've got a level 53 WC. I tied soloing some in the lower part of EV, and it's a very good place to grind for XP. The thing is, I don't know if I'm getting a penalty on SP by doing this. Can anybody give any feedback on the extent of XP and SP penalties for hunting lower level mobs? If you can give advice in terms of levels, it's more useful for me, as I can't see mob-level colors on my PC. (They all show as a sort of off-white.) Thanks for any help.

SP only gets a penalty when hunting light or dark blue mobs. If you are hunting solo or in group, SP follows the same dividing rules as XP, but I'm not sure it is in the same % though.

Thanks Orvieta.

i'm pretty sure that no matter the level difference the SP is always roughly 10% of XP wether the mobs is Red or blue.

No, the SP/XP ratio gets better at higher levels.

E.g.:
A level 20 monster gives SP of about 4% of the XP
A level 30 monster gives SP of about 5.5% of the XP
A level 40 monster gives SP of about 6.4% of the XP
A level 50 monster gives SP of about 7.5% of the XP
A level 60 monster gives SP of about 8.7% of the XP
A level 70 monster gives SP of about 10% of the XP
A level 80 monster gives SP of about 11% of the XP

Each level higher the monster, the SP ratio gets a little better. The difference can be noticable, but I usually don't pay way too much attention to it.