pulsating white round light that changed between white and blue

spring of 1967 siting  on my front door step,  carving my balsa wood soap box derby car for boy scouts.  I noticed a very large white light pulsating over the mountain range northeast of las vegas in the area of the test site and area 51.
the light a lot like a special event spot light but with out the tail was moving and pulsating a roundish white color that as it seemed to move in(forward) changed to a very   pale blue color still pulsating in a way.  it did not go all over the sky but seemed to blink in and out side to side above the mountain range know as sheep mountain.  the direction from were i was sitting it was were the test site is in nevada from las vegas.  after watching this light change color white to blue to white to blue i called my 17 year old cousin to come see it as she looked up to see it , it just blink out like snapping your fingers.
 I called the reveiw journal and sun newspapers and nellis airforce base to ask what it was but no one cared.  i was 11 when this happened.  saw the same light 30 years later  at  ufo meeting when colorado mufon showed films of ufos taken by normal people and the light i saw was on one the films shown taken by some hunters in colorado the same white and then blue pulsating light. also have had indirect  interaction with a man in black during this same time period a story for another time.  listen to you on jeff rense ,  decided to enter this as you always ask for any old reports,   thank you  ((name deleted))  albq, nm 505 ((telephone number deleted))
Date is approximate.  PD