demonstrates depth
To be honest there are many ways to add color to a slide
foreground
actin and myosin
it is a sewing thread
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technicolor! They colored in the film. Older movies that are refurnished from black and white to color are taken slide by slide, and the slide are colored in.
Coloured thread can also indicate the manufacturer of the rope
When doing applique you should use a fine weight thread, silk is often preferred, to match your applique or a shade lighter if necessary. When in doubt, or with multicolored patterns, gray can be used. On a side note, when piecing gray thread also works well as a "universal color".
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To demonstrate that friction is a contact force, you can place a wooden block on a flat surface and try to slide it. Then, place a heavier block on the wooden block and attempt to slide it again. The increased friction between the surfaces in contact will make it harder to slide the blocks, showcasing the role of contact force in friction.
On a mac powerpoint, you can control-click on a slide and go down to slide design, which lets you pick a scheme for all of your slides. Also, if you control-click and go to slide color scheme, you can pick colors and press apply to all. On a PC you can also do slide color scheme and slide design, but I'm not sure how to get there
Pointy. Colour itself depends on the thread.