Custom Header Color Options

Site URL: https://grey-cranberry-c4ar.squarespace.com/

I have a custom sticky header that works great, but I was debating changing the color. However, I'm unsure of what my options are. I tried using different colors in my custom css and some worked and some didn't.

Those that worked are: black, white, blue, navy, grey, tan, red, green, pink and teal. But colors like 'light blue' didn't work. I'd love to have my header as a sandy color so I tried tan, but its the wrong shade to go with the color scheme I've chosen. Does anyone know what the color options for headers are?

Note: I'm using version 7.1

What is access password?

Password is: kiwi22

Do you have an example of "light blue"?

Maybe light blue is invalid color code

You're right. It was an invalid color code. I tried making it into one word (ex. lightblue) and it worked! Also works for things like darkred, lightgreen, dark green, & darkblue (which appears to be the same color as navy).

@tuanphan For some reason, the code you helped me with previously, has stopped working. I want the header to be grey, but for some reason it's black. If I change the color scheme to one of the blue options it changes the heading to light blue. I'm really confused why changing the color in the css code won't change the header color anymore. 

Site url: https://grey-cranberry-c4ar.squarespace.com/

Password: kiwi22

This is the css that I'm currently using:

.tweak-fixed-header:not(.sqs-edit-mode-active) .header .header-announcement-bar-wrapper.shrink {
    background: grey !important;
}