false grey scale

Yesterday I opened a image in PS and it shows as if was in grey scale. I
cheked every thing I could think about and could'n find what was wrong.
I see the thumbnail whith Bridge as a colored image but as soon as it opens
is seems as grey scale one.
The image is refered as RGB 8 on the window bar and the filters and Adjust
commands are all as usual for RGB images (not greyed).
The PC is from a school, sone changed a preference or some thing else that I
am not able to find. What can it be?

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Ana Pereira




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