It might take a few days longer as custom blends, by nature, are not stocked. But, usually we have the standard colors available to collate to a custom blend within our normal lead times.
Absolutely, collating the bundles at the factory is a service DaVinci provides to eliminate the need for field shuffling which can result in inconsistent blending.
The tool assumes an equal percentage distribution of colors however you can specify different percentages for each color in your final blend.
We have made every effort to insure that our colors are represented accurately but there are inherent variations from computer to computer so we cannot guarantee that this is the case. The color tool is intended to be one step in the process and we recommend that you obtain tiles that are the colors you are considering.