Writing with Colors
I've found that using colors when writing on the whiteboard (or chalkboard, or projection, etc.) can be helpful in multiple ways. They're not just to make the lesson prettier – colors should be used with purpose. Also, you don't need many options; just blue, red, and green in addition to black should suffice (and most supply stores around the world will have these four colors).
Make Things Stand Out
This is the most obvious benefit, so let's get this out of the way. If there's a load of text written in black and just one word written in red, that red word is going to stand out. So if you need your students to pay attention to one detail in particular: write it, underline it, or circle it with a different color.
The trick is to use this sparingly. If a third of the text is in red, none of it will stand out. This is another reason that you really don't need more than four colors; the more colors you have, the less special each color is. In some situations, two colors will be enough; if adding another color would serve no purpose, then don't use it.
But you might have reason to use a lot of one color or to use more than just two colors on your board. Let's take a look at more options.
Group Things Together
Suppose you have a collections of nouns on the board and want your students to identify which ones are animals. You can circle these with blue (then circle the fruit with green, etc.). Or you could write expressions of agreement in green, disagreement in red, and uncertainty in blue.
When I construct complex sentences – say we're doing a unit on relative clauses – I use blue for one clause and green for another clause. We'll start with each clause as its separate sentence, then merge the two into one sentence, perhaps starting with a blue phrase, then the green clause, then closing with a couple more blue phrases. With the words in order, the students can read the full complex sentence. But if they just look at the colors, they can still identify the unique clauses. This helps many of them to understand how relative clauses work.
Let Your Colors Represent Something
Starting early with my beginner students, I use certain color designations and continue to use them as the students progress. Here are my most common schemes:
green for subjects / blue for objects / red for verbs
green for positive sentences / red for negative sentences / blue for questions
blue for past / red for present / green for future
Black, by the way, is used for neutral (if I use it a lot, then for things I don't want to stand out; if I use it just a bit, then for things I do want to stand out).
After using this method over and over again, students are quicker to identify the aspect (tense, part of speech, whatever) you're teaching through it. They're also more likely to identify mistakes ("Wait, there's supposed to be a blue word in here somewhere. Oops, I need to fix that.").
You've seen Insights to English use colors in our videos. We do so very purposefully. If you pay attention, you'll notice patterns (for those who don't, hopefully they still subconsciously identify those patterns). Colors can be used to create associations in the minds of learners. The more you repeat the same method of color usage, the more those associations will strengthen in the learners' minds. Especially if you instruct your learners to use those same colors as they write in their notebooks.
You don't have to choose the colors we use; choose a scheme that makes sense for you. If you don't have access to multiple colors of markers or chalk, use symbols instead (like circling the subject, boxing the verb, and underlining the object).
Language is full of patterns. As teachers, we should help students see those patterns, whether or not they realize that's what they're noticing.