@ Tjatur K. Gautama

Here is a Gist For MPS Color Codes 

The cells, which are part of the Suggested Replenishment line, can take different colors depending on the situation

Green: quantity of products which should be replenished to reach the expected safety stock considering the demand forecast and the indirect demand forecast.

Grey: replenishment order has already been generated, and its quantity still matches current data.

Red: replenishment order has already been generated, and its quantity was too high considering current data.

Orange: replenishment order has already been generated, and its quantity was too low considering current data.

The Forecasted stock line can also contain red cells, which means the stock will be negative during the period in question.

For More detail - refer the Documentation 

https://www.odoo.com/documentation/15.0/applications/inventory_and_mrp/manufacturing/management/use_mps.html

Hope It Helps!