ARGB Hex color not working in css html

Use rgba(255,153,128,1.0) instead of your hex value (though if that really is ARGB it's the same as #ff9980 in RGB - if you meant RGBA then you'll need rgba(255,255,153,0.5)).

the CSS3 spec says:

Unlike RGB values, there is no hexadecimal notation for an RGBA value.

so you will have to use the rgba(255,153,128,1.0) mentioned above.