At this point, we are concerned with ensuring the appropriate colors are used. The artist may submit a very rough idea of colors to be used in the final design.
If this was an original character design, the artist should ideally submit a few ideas or different color choices to make the decision easier for the client.
If the client has basic Photoshop skills, they can also modify the colors themselves and explore ideas that they like.
Again, at this point no lines or structure of the art should be changing, only basic color decisions.
If the client changes their mind about a pose or anything requiring new lines, reasonable additional costs should be passed on to the client.
There needs to be heavy back and forth between the artist and client at this stage, because once the colors are settled on, the rest is up to the artist to complete.