If you don't see the difference in blue/lilac points, then its poor breeding cause you should definently see a difference
Blue is a blue/grey looking; Lilac should be a much paler shade - almost pinkish blue. Read the color standard in points for siamese and you'll see what I'm talking about.
Here's the description for the basic solid point colors:
Lilac Point: Body color glacial white, shading, if any, in the same shade as the points. Points: frosty gray with a pinkish tone, the dilute pigment permitting the flesh tone to show through, resulting in a delicate peach blossom tone of the inner ears. Nose leather and paw pads: lavender pink. Lilac is a dilute color and may be pale, even when mature at 2 years.
Disqualify: Exhibits with dark intense tone of paw pads and nose leather.
Blue Point: Body color should be an even platinum gray of bluish tones, shading gradually into a lighter color on the belly and chest. Points should be a deeper grayish-blue tone, all points being as nearly the same shade a possible. Flesh tones of nose leather and paw pads to be a dark blue-gray.
Objections: Fawn or cream shadings.
Chocolate Point: Body color should be an ivory color all over, shading , if any, to be in the color of the points. The points should be a warm milk chocolate color, the ears, mask, legs, paw and tail to be as even in color as possible. Allowance should be made for incomplete mask, etc., in kittens and younger cats. The ears should not be darker than the other points. As a result of diluted pigmentation of the points, the flesh tones show through at the top of the nose leather, resulting in a burnt rose tone while the paw pads have a salmon pink color.
Objections: Exhibits with dark intensity of tone or paw pads and the top of nose leather, as seen in the Seal Point Siamese, shall be disqualified for competition in the Chocolate Point class. Commonly referred to as a spoiled Seal Point.
Seal Point: Body color should be an even pale fawn or cream, shading gradually into a lighter color on the belly and chest. Points should be dense, deep seal brown, all points being of the same shade. Flesh tone of nose leather and paw pads to be seal brown.
Objections: Black or gray shadings.
Red Point: Body color should be clear white, shading, if any, should be same tone as the points. Points should be a bright apricot to a deep rich orange-red "hot" color, the deeper the better. The red gene is a slow developing color. Two years shall be allowed for point color (mask, ears, tail) to intensify. Feet and legs will not have the same color development as the other points. They will appear as a cream white to a light apricot. Check near front paw pads and up the back of the hock for color. Kittens should be white in body with hot creamy points (mask, ears and tail). Nose leather and paw pads to be a "hot pink". Absence of barring preferred. Dark flecks on the nose leather and lips of older cats will be allowed.
Objections: Any pale or bluish tone to the points.
Disqualify: Black, blue or cream patches on body and/or point color (not to include dark flecks on nose leather), showing even slight tortie pattern.
Cream Point: Body color is to be an even white all over, shading, if any to be the same color as the points. Points may be any shade of cream from a deep cream to a pale cream. The overall impression to be a dull color as opposed to the hot tone of the Red Point. On deeper specimens, the impression will be a deep cream color with a dull bluish overtone. On paler specimens, the impression will be a very pale cream tone with a frosted overtone. Check near front paw pads and up the back of the hock for color. Deeper point color and absence of barring preferred. The red gene is a slow developing color, 2 years shall be allowed for point color (mask, ears and tail) to intensify. Feet and legs will not have the same color development as the other points. Nose leather and paw pads to be pale coral pink. Dark flecks on the nose leather and lips of older cats will be allowed.
Objections: Hot point color. Specimens showing hot red point color to be transferred to Red Point Class.