Q.Why Is Monkey Grass Lime Green?
Planted 6 different monkey grass pots around a large area around my flag pole. They are well spaced and not overcrowded. Four out of the six have been slowly turning lime green, while the other two are a darker, healthier looking green like my monkey grass in other parts of my yard. What do they need to darken up? What’s wrong with the soil, etc.? They all get the same amount of water/sun/shade.

Certified GKH Gardening Expert
They don't look sick in the photo. Are there any brown spots? Is it possible those are the gold variety? If not, you might try lightly fertilizing with a 10-10-10 slow release product. Also check for scale insects on the leaves. If the ground is not well draining, it can cause the plants to be overwatered, which can lead to yellowing. In that case, add soil amendments to loosen it up. Soil testing may pinpoint the issue.
These articles should help:
https://hgic.clemson.edu/factsheet/liriope/
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/compost-as-soil-amendment.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm