Way back in 2nd ed, there was a specialist Wizard that was called the Shadow Mage, and it got bonuses or penalties to the spell save DC depending on the amount of lighting that was in the environment around it.
Is there anything like that in Pathfinder?
there are feats tenebrous spell, umbral spell, and shadow grasp which make shadow/darkness spells cooler.
also sorcerer shadow bloodline and the wizard archetype shadowcaster
Hmmm. Close, only Tenebrous Spell does that, as does Shadow Well from the Sorcerer bloodline, and the Shadowcaster sorta does overall if you are willing to give up your arcane bond.
Out of the ones you listed, it looks like only Shadowcaster (combined with some form of school specialization) and Tenebrous Spell do that. Even then, you only get bonus spells, not really increasing the DC or damage.
Does Ultimate Magic have these feats and mage archetype in it, or do I have to get Inner Sea Magic to get these in print?
Are they light dependent, as in the amount of light in the area when casting affects how potent or difficult to resist the spell is?
The answer to your question is in the links provided by asthyril.
edited after original posting