GRAYSCALE HELP about colors

Hi…i have atomstack A5 pro 40W and i have only GREY COLORS…i dont have brown grayscale…idk why…im engraving 90angle because 0 angle is big beam… plywood birchň

i seen people grayscale is colored grey,brown …every 10%+ different color…and im making only GREY color…BLACK = GREY =until WHITE

can i add here my grbl settings? if everything i have fine or somewhere is error?