Please don't base your teams around certain colors, it gives you a severe lack in diversity with types.
The problem with Lanturn and Omastar is that you already have 2 weaknesses to Ground on your team. 3 Ground-weak Pokemon is a no-no. A good Water-type I shall recommend would be Jellicent cos it's bulky, has not-too-shabby Special Attack and learns good moves.
Altaria is very much lacking in offensive power, try using a Fire-type instead. I recommend Darmanitan or Chandelure.
Jumpluff is more defensive so this means it won't hit really hard. For a good offensive Grass-type, try Roserade or Breloom. Another much better defensive Grass-type would be Ferrothorn due to having a ton of resistances.
Having Jumpluff and Altaria on your team at the same time is bad cos that gives you 2 quad-Ice-weak Pokemon and Ice is a very popular type offensively. Having two Pokemon with a 4x Ice weakness definitely spells you trouble, especially against Brycen as well as N's Vanilluxe near the end of the main story. Try replacing them with any of the Grass-types I mentioned above and the other slot should go to Darmanitan or Chandelure cos a lot of Pokemon you will run into in Unova have Fire weaknesses. Darmanitan if you want a Physical attacker or Chandelure if you want a Special attacker.