If the colour of the stains is sufficiently marked (black, pink, reddish-brown) to be immediately visible and if they cover an area not less than half that of the grain, the grains must be considered to be yellow grains.
Má tá dath na ruamanna soiléir go leor (dubh, bándearg, donndearg) is gur féidir é a fheiceáil láithreach agus má chlúdaíonn siad achar nach lú ná leath achar an ghráinne, ní mór glacadh leis na gráinní mar ghráinní buí.