I tried to get the correct colors for every school who has competed in the Contest. A few (including the Home Schools) were impossible to find.
The table below shows each color name I found being used for a school, how many schools, it was used for, the color code for that color, and where I got the color code.
| 243 | white | #FFFFFF | CSS Specification |
| 124 | gold | #FFD700 | CSS Specification |
| 120 | black | #000000 | CSS Specification |
| 86 | red | #FF0000 | CSS Specification |
| 66 | orange | #FFA500 | CSS Specification |
| 63 | navy | #000080 | CSS Specification |
| 54 | royalblue | #4169E1 | CSS Specification |
| 53 | blue | #0000FF | CSS Specification |
| 47 | purple | #800080 | CSS Specification |
| 42 | maroon | #800000 | CSS Specification |
| 30 | green | #008000 | CSS Specification |
| 27 | columbiablue | #B9D9EB | Columbia University |
| 19 | kellygreen | #4CBB17 | Wikipedia article "Shades of green" |
| 18 | grey | #808080 | CSS Specification |
| 18 | silver | #C0C0C0 | CSS Specification |
| 16 | scarlet | #D00000 | University of Nebraska at Lincoln |
| 10 | forestgreen | #228B22 | CSS Specification |
| 9 | vegasgold | #B4975A | Vegas Golden Knights, per teamcolorcodes.com |
| 7 | brown | #A52A2A | CSS Specification |
| 5 | cardinal | #8C1515 | Stanford University |
| 4 | burntorange | #BF5700 | University of Texas at Austin |
| 4 | crimson | #DC143C | CSS Specification |
| 4 | oldgold | #CFB991 | Purdue University |
| 3 | huntergreen | #355E3B | Wikipedia article "Shades of green" |
| 3 | yellow | #FFFF00 | CSS Specification |
| 2 | cherry | #CC252C | color-name.com |
| 2 | darkgreen | #006400 | CSS Specification |
| 1 | athleticgold | #EFB21E | Oakland Athletics, per teamcolorcodes.com |
| 1 | boldgold | #F0D473 | encycolorpedia.com |
| 1 | brightgold | #FFDB51 | color-name.com |
| 1 | burgundy | #800020 | Wikipedia article "Burgundy (color)" |
| 1 | carolinablue | #7BAFD4 | University of North Carolina at Chapel Hill |
| 1 | cobaltblue | #0047AB | encycolorpedia.com |
| 1 | corn | #FFCB05 | alias of "maize" |
| 1 | cream | #F5F1E7 | University of Nebraska at Lincoln |
| 1 | ivory | #FFFFF0 | CSS Specification |
| 1 | lightgold | #F1E5AC | color-name.com |
| 1 | maize | #FFCB05 | University of Michigan at Ann Arbor |
| 1 | metallicgold | #D4AF37 | Wikipedia article "Gold (color)" |
| 1 | myrtlegreen | #21421E | Wikipedia article "Shades of green" |
| 1 | newgold | #FFDB2D | color-name.com |
| 1 | teal | #008080 | CSS Specification |
Obviously some of the sources I have there are better than others. The CSS spec is the most authoritative, but for a school that uses Columbia Blue, Columbia University's reference is also authoritative.