Slime mold is an algae that grows on top of the soil. The soil discolors to a medium/dark green, or a orange color. Algae will negatively effect the germination and growth of your newly seeded lawn. The condition itself is caused from too much water and/or an excessive amount of compost in your soil.
NOTE: If slime mold becomes a problem, allow the affected area to dry slightly, but remember moisture is necessary for continuing germination. (Supplemental hand watering may be advantageous
in these areas). Spray the affected area with fungicide. Check with your local Nursery or Turf Supply Store for a product (such
as FORE or DIATHANE WF) that would be recommended for slime mold control.