>>mygrid.column1.dynamicbackcolor="iif(somecondition,rgb(50,255,0),rgb(255,255,255))"
>this command colors the whole column. I need a single color to be coloured. What if I wanted to have a chess board in a grid ?

you have to use the somecondition part to get whatever pattern you want.

For example, grid bound to a cursor could achieve chessboard pattern with something like:

mygrid.column1.dynamicbackcolor="iif(mod(recno('mycursor'),2)=0,rgb(0,0,0),rgb(255,255,255))"
mygrid.column2.dynamicbackcolor="iif(mod(recno('mycursor'),2)=1,rgb(0,0,0),rgb(255,255,255))"
mygrid.column3.dynamicbackcolor="iif(mod(recno('mycursor'),2)=0,rgb(0,0,0),rgb(255,255,255))"
mygrid.column4.dynamicbackcolor="iif(mod(recno('mycursor'),2)=1,rgb(0,0,0),rgb(255,255,255))"

Don't forget to set Sparse to .F.