How to write a css selector for element containing this attribute:  
style="background-color: rgb(128, 128, 128); "

I want this selector to work even if there are other values contained in the element attribute.
The CSS Selector you provided would select any elements with the specified style attribute value of 'background-color: rgb(128, 128, 128); '. You can use an attribute-specific CSS selector along with quotes around your value to ensure that it is treated as one string instead of multiple values. For example, `[attribute='value']` will match only elements with the specified attribute with a value matching 'value'. If you need to target specific values within the style attribute, you can also include additional square brackets after the value and set conditions using boolean operators such as '!important' or'*= '. For example, `background-color: rgb(128, 128, 128),!important;` will select only those elements whose style attributes have both 'background-color: rgb(128, 128, 128)', but not others who may have 'background-color: rgba(...),...;'. Additionally, be sure to use proper syntax when defining your CSS rules. For example, missing commas between property names orvalues can cause errors.