user: Question: What is the number of colour with the regisration number of MG-509?
Columns: ['Pilot car No.', 'Colour', 'Serial No.', 'Engine No.', 'Registration No.']
Types: ['real', 'text', 'text', 'real', 'text']
Sample row: [1.0, 'Gawler Cream (Body No. six)', '8-1001-M', 1001.0, 'MG-501']
SQL:

assistant: SELECT COUNT("Colour") FROM "Table" WHERE "Registration No." = 'MG-509';