I actually used to DO color analysis. BTW, I’m a winter.
The best way to figure your color season out is to go ahead and actually test what colors work best on you, in natural light.
Quick test:
Get a swatch of pure blazing white cloth - as white as white gets, no shades of cream or gold. Also get a swatch of beige cloth (any golden brown to dark cream color, not grayed or purplish). Swatch size is best if it is at least 6-8 inches wide and as long as the distance across your shoulders (so you can get a clear ‘frame’ of color). Borrowing someone’s shirt/skirt/jacket will do just as well.
Hold each one up under your chin, so the (natural) light reflects from the fabric onto your face, and look in a mirror. Swap back and forth and look at the color of your eyes (including the whites), your teeth, and the space under your eyes. One will definitely make you look better than the other, though it is okay if neither is perfect. If you want to be utterly sure, do the same for electric pink and bright orange.
If WHITE (and/or pink) looks better, you are a cool season (meaning, no yellows in the colors), if the BEIGE (and/or orange) looks better, you are a warm season (meaning, yellows are fine, blues are usually bad). If you aren’t sure, check for patchiness in your skin showing up more in one color than the other, or have someone else look for the under-eye circles seeming deeper/ickier with one color.
If you are a cool, get a nice french blue or solider-blue (very gray-blue) swatch and a royal or cobalt blue (clear/bright/non-grayed) swatch. If the french blue (with the gray) looks better than the cobalt, you are a Summer. If the cobalt looks better, you are a Winter. You can do the same with a dusty lilac (summer) and a pure royal purple (winter). Usually, summers are lower contrast (between skin, hair, and eye intensities) than winters, but not always.
If you are a warm, that’s harder to describe, partly because I simply don’t find that many of them (and partly because they tend to be able to wear more crossover colors). The usual test is peach (pale pinky-orange) vs. deep brick orange. If peach is better, you are a spring, if brick is better, you are an autumn. Chartreuse (spring) and Forest green (autumn) are also possible test colors, though forest looks good on many people (very close to the middle of the color line), where brick is more likely to really show up the difference.
BTW, the seasons are not necessarily the colors that show up in that season-of-the-year, as most seasons in nature have a wide variety of colors. But some of the most obvious colors are more primary in those seasons - such as oranges and burnt browns in autumn, pale yellow-greens in spring, black and white in winter, and soft flower-pinks and gray-blues in summer.
Most people can get away with some colors outside their season. They won’t usually look utterly radiant and stunning in those colors, but good enough. If someone raves about a color on you, make a note of it - it is probably in your season. You can also use this power for evil - I met someone who is a winter but would wear spring colors when she wanted to take a sick day - everyone thought she looked ill, so nobody suspected she was playing hookey the next day. Crossing both the intensity and cool/warm line at once tends to do that.
And then, just to make things messy, there are the ‘outside the box’ sorts of people - Such as springs, who have the hardest time getting the right colors, IME - they tend to have a more limited selection based on their individual coloring intensity, some that just will not do, even if they are technically in the right season. And warms tend to have more crossover in the dark/light range as well, for the same reason - the intensity of their coloring can affect what works, more than for cools (not sure why, but seems to hold true). People of color have more freedom to cross over all over the place because darker skin tones tend to show less of their undertone when reflected light hits.
In other words, if you look good in it, you look good in it, and sometimes that won’t be smack in your usual color season.
The quick version I give on the color seasons (similar to flodnak’s version) is:
Winter: cool (blue-based) and clear (think icy or jewel-tone)
Summer: cool (blue-based) and grayed (think powdery or pastel)
Autumn: warm (orange/yellow-based) and dark (think earthy/rich)
Spring: warm (orange/yellow-based) and light (think sunny)
flodnak, you want to maybe buy your mom a swatch book for your season? I know that different companies still sell them, usually pretty cheaply. If you can’t find one, email me and I’ll get you in touch with someone who has them.