The audio and visual senses of humans have a limited spectrum. These spectrums have been measured by humans, and from them we have the rgb color model, the cmyk color model, grayscale model - and in music, we have the HZ scale.
Successful art and music, for the most part, depends on proper use of the spectrum. Improper use can be used in extreme situations, but those are exceptions.
Why do some stereos (and nearly all audio players) have a Graphic Equalizer? The answer is simple. Speakers sound different. Songs sound different. A song might sound really bad on your speakers, because it emphasizes bands your speakers have low response on. The song artist never heard their song on your speakers. So a Graphic EQ gives you to the chance to correct the sound.
The same is true of monitors - they have brightness/contrass/color temp to help you compensate for errors in the physical hardware. Running a monitor at a different altitude, or in a different climate zone, or near a power plant - all of these can affect how the monitor displays certain shades of certain colors.
In the industry, its known that there are no magic numbers that will make it perfect on every system; all one can do is make it sound as good as possible on as many different stereos or monitors as possible. (or to make sure the ones owned by your target audience display it well).
But even the mighty iphone cannot escape the unpredictablitity; there are slight differences from one iphone screen to the next; and the lighting conditions its used it, and the settings of the user - mean you still can't predict exactly how something will look or sound.
What the industry has are methods for maximizing the output of your effort. And those are hard to find on google, because most of those are inside the minds of the people who use them; what reason do they have to make tutorials? they're too busy making art, music, or games.
So as i discover some of these methods and 'golden numbers' i'd like to share some of them with you.
Image Color Spectrum: Even colorblind people can adjust colored images. First, you find the DARKEST spot on the whole image. Is it 100% black? it should be!
Find the brightest spot on the image - is it 100% white? it should be!
Human skin should be a ratio of 8 parts yellow, 5 parts red, and 2 parts blue. It doesn't matter what race someone is; black, caucasian, oriental - the actual levels will be different, but the ratio of the colors should stay the same. If they aren't, then your photo isn't correct. However it may still look great - because your monitor isn't correct. lol.
Typical commercial monitors have overpowered blue. This makes things look better, but its less accurate. Its why the windows xp default desktop looks so good. The blues are powerful, relaxing. They then make the yellows in the green grass appear even brighter. And red really pops with all that blue around.
Because human eyes are adapted primarily for survival, things are distorted to make the data easier for the brain to interpolate; When a caveman sees a sabertooth tiger, the yellow/orange of the tiger really pops against the green jungle foliage; because the green is full of blue too, but the tiger has absolutely NO BLUE in him at all.
The eye then readjusts the tiger's color to maximize use of the spectrum; the tiger becomes redder, and the leaves on the trees become bluer. The human can now see the tiger very clearly even at a great distance.
The same things work in sound; especially noticeable in rap music when they use classical and ambient music samples overlaid on nasty and brutal lyrics; each one makes the other 'pop' more.
Consider how you're using the spectrum, and what it means for your project. You don't have to follow the rules to a T, but you should be in the ballpark of believability, or at least desirablility.
One thing that its traditionally used in games to control colors, is to make the background lighter than the foreground - make everything lighter. There should be no pure yellow in the background, because pure yellow is what you use for powerups! Powerups, bullets, enemies, and platforms should pop; everything else should be toned down.
Complimentary colors are also important; not opposites, but near opposites. Not blue and yellow, but definitely aqua and orange. Purple and green. Aqua and gold. These color schemes are more interesting than basic red yellow blue stuff.
And when increasing brightness, use hue instead. Red doesn't fade to pink, it fades to orange, then yellow.
Purple doesn't fade to lavender, it fades to blue and then white.
And light blue fades to aqua, then white, not just constant shades of lighter blue.
Green fades to yellow. Brown fades to either orange or yellow. Using colors for brightness will give your images a lot more depth and pop.
Notice how green becomes yellow instead of light green, purple becomes blue, etc.
When making 4 frame running/walking animations, the frames should be step, midstep, step(opposite leg), midstep(opposite leg). However, the midsteps should not be halfway in between; instead, a foot should be very close in midstep to where it is in fullstep; then when we switch to the opposite leg fullstep, the action will really 'pop' in those frames, and your character appears to put real energy into his footstep. Also making the inbetween frames closer to their next frame will help keep your legs from 'flickering'.
If you want really fluid running, use a 6 frame step, and rotate the feet like bicycle pedals; you need 3 positions to indicate circular motion (only 2 results in just flickering). So we use 3 frames for one leg forward doing its bicycle rotation, and then it stays on the ground while the other leg does its rotation for 3 frames.
For jumping, you want 3 main frames; jump up, top of jump, and jump down.
When jumping up, one leg is forward, and when jumping down, the other leg is forward. Top of jump animation is where the legs switch; its the animation he takes as his yvelocity is reversing from negative to positive.
Reuse frames whenever possible; a duck frame is a good one to use for landing from a jump, or the very start of a jump.
When arranging the body and head, remember that the whole purpose of the legs and arms is to move the torso; your torso should be moving in a slight circle as the character goes thru his run animation; and the head should be compensating to make sure he's always looking at the same angle, no matter what his body is doing.
In reality, all we do when we walk is fall. We fall forward, then catch ourselves in the nick of time. Walking is a series of falls.
Anything that you want to look good should be in 60 fps. If your game slows down in 60, you need to improve the code so it doesn't. While 3d games like GTA and online games have to limit their framerate for other reasons, you don't. Stuff made in 30fps (that's twos in the cartoon business) only look as good if they're planned in twos; that is, if you have a blur coming off the side of the baseball, or the baseball is elongated - to show speed. If you're not making cartoon speed simulations though, and dealing with realisticly defined sprites - as 99% of all game creators are - then two's won't cut it. You need ones. 60 fps.
When making parallax layers, try using the Golden Ratio to match their distance, size, speed, and lighting. Try to get the most impact out of the fewest layers possible, by drawing spaced out layers. For instance, jungle close, jungle pretty close, and jungle far away aren't a good match, because the top two layers have such similiar lighting.
Instead, jungle close, jungle medium, and jungle far away would make a better combination, as they'll use a larger array of the spectrum.
Try using 8-3-1 ratio for them. top layer, xvelocity=-8; middle layer, xvelocity=-3; bottom layer, xvelocity=-1.
Then when you add a transparent blue 'air' layer on the lower layers, adjust the transparency of that layer accordingly; middle layer is at 36% transp; bottom layer is at 12% transp. (8-3-1) - top layer is 100(100/8=12*8=100), middle layer is 36(100/8=12*3=36), bottom layer is 12(3/8=@4. 4*3=12). Remember, we're going 8 and 3 over and over, so the bottom layer is 3/8 of the layer above it - which is 3/8 of the layer above that. If you want to know more, read up on the Golden Ratio and learn how it works. After centuries, humans have figured out some pretty solid rules for certain things.
In almost any case, the ratios of things are more important than the values themselves; from markets to politics to programming to painting. To become great at any of these things, it really really helps to learn to see things as ratios, instead of absolutes.