Match a Color and Gradient

[Mary.M.Lewis]

How do I match a color and gradient in an existing piece of line art? I tried
to match it using the RGB scale, but couldn't do it. Is there a way to sample
it, or perhaps great a lineless rectangle that contains the proper
color/gradient that I can use to cover up what I want to eliminate?

 

[Jezebel]

Use a graphics application (which Word is not). They all have an eyedropper
tool or equivalent, that copies an existing colour and applies it to
something else.