I want to show grid current row with Forecolor=RGB(0,0,255).

Add a custom property to your grid class called nRecNo and initialize it to 0. This code in the grid's Init()

*** Set up for highlighting current row
This.nRecNo = RECNO( This.RecordSource )
This.SetAll( 'DynamicForeColor', ;
	'IIF( RECNO( This.RecordSource ) = This.nRecNo, RGB( 0, 0, 255 ), RGB( 0, 0, 0 ) )', 'COLUMN' )

And this code in AfterRowColChange():

Thisform.LockScreen = .T.
This.nRecNo = RECNO( This.RecordSource )
This.Refresh()
Thisform.LockScreen = .F.