[It's not an unreasonable argument. Something in him chafes at the idea of ceding some of the control he has over the house's security measures when he's always had it, though. If he's in control, he's safe.

[But realistically, keeping these methods to himself isn't the most practical. Mello gains nothing from the house being compromised and has no reason to keep him out -- and the spell wouldn't stop Near if Mello tried that anyway. So this is fine.]

You need to start with non-coloured spells to familiarize yourself with how magic works; colour magic is more complicated than those. Indigo isn't the colour you are most suited for, but you should be able to learn it with some work.

[So, yes. He'll agree to this.]