Question

I am working on the 2nd problem...I am not able to produce a color I want
for a polygon I have created. It is not related to the normal--the shades
change with rotation, but the picture is in grey mode, real colors are not
rendered. Is there anything else I need to add?

GlBegin(GL_POLYGON);
glColor3f(1.,0,0);
v1,
v2,
v3...
glEnd();

Answer: To set the color use the function provided: set_colour(float r, float b, float b).

Question

I am wondering for assignment #1, problem 1, are we supposed to know Y for
each color (R, G, B) in addtion to their x-y coordinates?

Answer: You only need to compute x,y,z. You do not need to recover X,Y,Z.
From the chromaticity coordinates you have to compute r,g,b which are the
RGB-space coordinates, and using those you can compute the actual color.